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x=c x x = 5x x = 0x x 5x 0x x = 5x = x = 0x 7 x y=0 xy= x y xy= x y x= y x = y () x=0 x= ()5x= x= () x= y x=7 y y= (4)x = y x = 5 y = 8 (x )(x )=0 x= x= x ax=b ()a 0 b 0 x 0 ()a 0 b 0 x 0 ()a 0 b 0 x 0 (4)a 0 b 0 x 0 ()6 x= ()(x 4)(x )=0 9 x =0 0 x

5x=0 5 0 x x =5 5 x y ay b=c a b c y ()x =0 ()5x =x ()x y= (4)5xy x=0 x x ()x a=b ()x b=5a 40 5x =7 5 =7 0 =7 8=7 x 5=4x = ( ) 5= =4 ( ) = 0 x 5=4x 60 60 = 0 = 6 60 (a ) (a )x=5 a 0 x = 5 a = 0 (a )x 5 a + x ax =x ax =x ax x= (a )x= a = a x = a x ax= x =a ax=b 4 (a )x=0 4 4x = 6x 6=0 4x = x= x= 6x 6=0 6 6=0 x= 6x 6=0

4 x y=0 xy= x y x y=0 x y xy= x y ab= a b xy=k x y 0 x y xy=0 x y=0 x(x y )=0 4 x=y x 5 = y x 6 = 0 y 44 7 5 x 7x x=5 ()a 5 () x ()a b (4)x 4 y (5)a b (6) () 5 0 () () 5 (4) 5 (5) 5 (6) () () 00 () 0 (4) 0% 65% 0 (5) a b 80 (6) 4 R ()x

()x 5x 45 x =0 x x = x 0.5 x x y= x y= x y x y ()x y=0 ()x y= 46 x =x x x x =x x x x = x x= 8x=8 7x x =x 5x =4x 4 x 7=x 5 0 0x=9x 6 8x =9x 7 0x 6x=x 8 x =5x x 47 ( ) 0 0 x(x )=(x ) x x= x= x =5 x x(x )=5x x=0 0

48 ()5x=40 () x = 9 () ( 5) x=8 () ( ) x = ()x= () x= () 8 x = 4 (4) x = 0.5 5 49 x x = 5 ( x)=0 5( x) 4x=0 5 5x 4x 5x=0 5 9x= x = 9 x + 5 = 5 x 7 x + 7 = 4 5 x = x x + 4 ( ) = 7 4 5 x + 5x 5 = 0 6 5x 0x + 6 = 7

y 5 7 = y 6 4 8 [ 4 x ( x )] = 4 x 50 0 n n x 4. x.5 = 0 0. 0. 0x 5 4 0x + = = 0 40x 5 4 90x=0 0x = 7 x = 7 0 0. 4x + 09. 0. x 05. 00. + 00. x = 05. 0. 0. 0 x 4. x + = 0 0. 0. 0.x 0. = 0.7x ( x ) 4 7.5 = 0.0 x.5 0. 0 0. 0 0. 5x 0.4(0.5x ) 5 x = 0. 04 0. 5 5 x x= x= 5x=5 5x =7 5x + 7 = 6 4 5 0.8x = x 0

0.8x = x = 5 x 0 0.8x = 4 5 x = 4 x =5 x x =5 x=7 x (x )=5 x= x= x = 5x =0 x =7 4 5 x =0 5 ( ) 4.4 0. x x 4 0.=.4 x=.4 4 0.= x=0.4 0.4 6 A 48 B 70 6 4 54 5 / 6 / x 5x x=6 5 x = 4 4 4 4 9 9 6 6 55 x 0

(x )=0 (x ) =0 4 x (x ) 5 4 x 5 = x x=6 x = 6 x (x ) x (x ) = (0x x ) 4 x= x =6 6 6 4 7 6 56 84 x x = x x 5 4 x x 7 6 x=84 57 4 0 5 0 4

x 4 x 0 x 5 4 x 0 0 x 0 5 4 x 0 0 = (x 0) 5 4 x ( 4 5 x 0) 4 5 x 0 0 = (x 0) 4 4 x = 50( ) x 0 = 70( ) 5 70 50 8 47 9 5 5 60 58 90% a 90%a = = 500 9 5.% x 90%x 500=500 5.% x=640 640 0 0 5% 59 s v v s s t t

() s s =s v t v t =s( (v v )t=s) t =t =t () t = t s s = v v A B 00 A 70 B 5 x (70 50)x=00 x = ( ) = 0 0 x 50x 70(x 0.5)=00 y (70 50)y = 00 50 B A 00 x (70 50)x=00 A B A B x x=(70 50) A B 00 70 50 A B x 70x 50x=00( (70 50)x=00) x=0 0 8 x x x = 70 8 50 8 = 8 70 50 5 4 A B A 5 B A B 550 50 A B 00 () () ( B A ) 60

400 450 50 () () x () (450 50)x= 400 7 x D n 0 8 6 ()(450 50)x= 400 x=4 7 4 680 60 480 () () () (4) 6 = = = 0 5 = x + ( )x = x = 4 0 0 5 4 0 7 80 0 5

0 6 6 ( ) = ( = ( ) 4 5 6 x 5 (x 4) = (x 4) 6 x=840 (840 4) 448( ) 448 A B 0 A B 5 A B 6 0 / 6

64 x = 0 5x y 6 x y = ()5x y () () x 5 0 6x y x y 4 x y z x 0 x y = 5x y (4) x y z = (5) y z (6) x = 7 x y z z x 5 65 5x y = 5 x y = () x = y 5 8x 5y 6 (5 7) () ( 4) 5y 4 = x 5 7 x y 8 4 (x y) y 5 () (6 9) 5 (x y) y = 7x 9y = 4 (4) ( 5) 9x 7y 97 66

x y = k x y k 5x y = k x=y x = k x = k k k k x y = k kx (k )y = 0 4x y = x y k kx (k )y = x = x = ax by = 0(b 0) c y = y = c 4 a b () x ay 7 = 0 x ay = 0 () x y 5b = 0 x y 5 = 0 67 () () () ax by=c(a 0 b 0) x y x y = = 0 xy = 0 y = x y = x 68 x( y) y( x) y=ax b y=ax b y x x x 4 x y=ax b y x = m 5 x y y = n 69

4 x = a 5 y = b z = c 70 x = y x y = 5 ( y) y=5 y y 5 y= x = y = x = y = x 5y x y = 8 x=8 y (8 y) 5y= 6 6y 5y= y= 7 y 7 x y = 7 x = 8 = 0 0 y = 7 x y = 4x 9y 8 y = x x 4x 9 = 8 4x 6x 8 0x 5 x x = y = x = = = y

x 5y = 6 = m n 5 x 4y = 5 m n 4 y x = 5 x y = 5 4 5y x = 5. x = x y z 7 x y = 8 5 x y z = 6 y z = 7 x y z = 4z x = 7 7 ( ) ( ) ( ) ( 0) x y 5 x 4y = 8 y y= x = y = x 5 x y = x y = 4x y = 6x = x = 6 x y 6 y = 5 x = 6 9 5 y = 9 x 5y = 5 4x y = 5 4 x 0y 00 x 9y=45 y=55 y=5 y=5 4x 5=5 x = 0 x = 0 y = 5

x 4y.9 x y = x y 5 5x y = x + y + x y x y = = 6 4 y z 6 4(x y) 5(x y) = z x = x y z = x y 5 5 y z x = 5 6 y z 7 z x y = 7 4z x = 7 ( ) 4 5 7 ax by = c a x b y = c x y = 5(x y) = y x y= x y = 5x y = 0 5x y 0

x + y x = y + + = 6 () 5 () (x y) (x y) 5 x y = 5 (x y) y = 5 (x ) y 5 () (4) 5 5(y ) (x 5) (x y) y = 74 x y = 6 5x y 6 x=6 y 5(6 y) y 6 80 0y y 6 9y 54 y 6 x = 4 y = 6 x = 4 y = 6 x 0 x 7y 0 x 9y = 4 y 5 y 6 5a 4b 5 x y 4 a b 4x 5y 75 ( ) ( 0=0 ( ) ( ) 840 4 8 4 9 x y

4x 8(x y) 840 4y 9(x y) = 840 x = 50 y 0 50 0 56 4

76 5 x + x 4 5x 8 0 5 S= r 6 x 0 7 x y z 0 8 x 0 9 0 0 x x 77 ()5x = 0 ( 5 ) 5 5 ()x =x ( ) ()(x ) 5 ( 6 4 ) 7 8 4 4 ()5x 6 ( 0 ) ()(x ) 4 ( ) 78 ax b ax b(a 0) 0 () ax b ax b(a 0) b b a a x x a a () ax b 0( x a b a 0)

a b ax 79 () () () (4) (5) x + 5 x + x 5 x x x 5 x x (x 4) x (x 5) (4x ) x x 4 6 4 x 6 68 ( ) 9 ( ) ( ) 8 7 ( 4) 56 8 7 0 8 a x (x a) (x 4a)=4(5 x) 5a 80 x x 0 x x x 4 ( x) 4( x) 4x x x 0 x 4 4x x

(x 4) x + x + x 4 5x x 4 x x 4 6 50 8 4 x a x b x a x a x b x b x b x a b x a x a 4 x b

()x ()x ()x (4)x ()x 4 ()x.5 ()x 0 (4)x (5)x 5 (6)x 6 8 x x 5 0 5 x 5 0 x x x x 5 0 x x 5 0 x x 5 0 5x 5x 5x x 4 5 5x x 8 ( ) 0 ( )

(x +) 5( x + ) () = 6 () x + x + = 0. 05. () x x ()(x ) 5 4(x 7) 84 x 0 x 0 x 0 () x 0 () x 0 85 k 5x k 4x 9 x=9 k 9 k 0 k k k 6 0 x 7 5 x x 9 x k x 5x (k )=x k 86 ( ) 87 x 0 x x 4 x 4 x

8x 7 x x x 0 x x x 0 x 0 4 x 7x x x () x 6 4x 5 () x x x x 5 7(x ) (x ) x x 4 x x () 5x 4x (4) x 6 x 7 x 6 x ( x + ) x 8 4

= x 5xy + y + x + xy y xy = xy = (x y) x + y x 5xy + y = x + xy y x 0x 0y + y = x + 6x + 6y y x 0( x + y) + y x + 6( x + y) y x y = 7 7 5x + 5y x y = 7( + ) = 5( x + y) a= b= ()ab a b ()(a b)(a b) ()a ab b (4)(b a)(b ab a ) 4a b ab 4a b a= b = m n m n 0 6m + 8n 5x + 6y 4 x = y 4x y 5 a b = b a a(a b) 8(a b) b 4 8 a c e g 7 a c + e + 4g 6 = = = = b d f h b d + f + 4h 89 () 6 () a 0 b 0 c 0 a ab a a c c b a 0 b 0 c 0 7 5

a ab a a c c b a ab a a c c b a a ab c b ab c b x x x x 0 x 0 x x = 0 x = x =0 x= x x x = (x ) (x )= x x = x x x x = (x ) x = x x = x x x x x x a 0 b 0 a b ab a b ab () x x x () a a 4 90 a () () S = a 4a 9

4 = = 4 4 4 4 5 5 4 4 5 4 5 75 = = 5 4 5 4 4 5 4 5 = ( ) = 5 4 5 4 4 5 4 5 ( ) 5 4 5 4 4 5 5 4 5 5 4 ( ) 4 5 (y x) (x y) n+ (y x) n+ 4 (x ) x x x ( x ) ( x ) 5 5a b 5 ab ab () h () S 6 x y x xy y 5 7 ()a b (ab ab ) ()(ab ab ab ab ab ab ) 9 a 7 a a=a 7 =a 4 a a 7 a=a 7 =a 6 ( ) ( ) (a 4n a n ) a n (a 5 ) m a m a m

a m a m 4 a 5 (a ) 9 [(a ) (a 4 ) ] (a 6 ) (a ) [(a ) (a 4 ) ] (a 6 ) (a ) =(a 6 a ) a a 6 a 8 a a 6 a 8 6 = a a 6 [(a ) (a 4 ) ] (a 6 ) (a ) = a 6 a (a 6 ) a 6 (a 6 ) (a 6 ) a 6 = (a 6 ) =(a 6 ) 0 =a 0 = ()a 7 a 5 = ()( x) 5 ( x) = ()x n =x n (4) = m m 7 (5)(m ) 5 (m m 5 ) (6)(5x y 4 z 5 ) ( )=5x y z (x m+n x m+n x m ) ( x m ) 94 () (a b)(a b)=a b () (a b) =a ab b () ( ) (a b)(a m ab b ) = a b (x )(x ) (6x 4)(x ) (x )(x )=(9x 4)=8x 8 (a b c)(a b c) (a b c)(a b c)=[a (b c)][a (b c)]= a (b c) =a b bc c a b c a b c ( y x)(y x) = (y x)(y x)= (4y 4 9x )= 4y 4 9x

=( x y )( x y )=( x) (y ) 9x 4y 4 ()(ab b)(ab b) ()(a b)(a b) ()(4x x)( x 4x ) (4)(x x )(x x ) ()( a b) ()( x y)(4x xy y ) ()(4y 7)(49 8y 6y ) (4)(a b c d) 95 x x =x 5 (x ) x =6 (x ) =x 6 ()a a a 4 ()[(a ) ] 4 ()a a a 4 =a ++4 =a 9 ()[(a ) ] 4 =(a ) 8 =a 4 ()x x 5 ()a (a a ) ()ab ab (4)xy(xy x y) (5)x 5 y(y 5 x x 5 y) ()(y 4 ) ()(x y) ()(x y) 5 5 ab c (4)( xy ) (5)( x y z) (6)( ) 7 6 48 96 a b =(a b)(a b) ( ) ( ) ( ) ( ) ( + ) ( ) 98 98 =(98 )(98 )=00 96=9600

()0 8 ()4 4 ()(98 ) (4) 6 8 ()00 998 ()0 9 () 0. 9.8 (4)98 0 97 ( ) = ( ) = ( ) = = 6 9 ( ) 4 () () () (4) (5)( ) 6 (6)[( ) ] (7) 4 8 98 (a b) =a ab b a b (a b c) b c (a b c) =a b c ab bc ac ()(a ) ()(a 4b) ()(4b ) (4)(5 0) () ()49 ()99 (4)57 99 (x )(x )(x ) (x )(x )(x )=(x x x )(x )= (x x )(x )=x x x x 9x 6= x 6x x 6

( a )( a + )( a + ) 4 ( a )( a + )( a + ) = ( a )( a + )( a + ) = 4 4 4 ( a )( a + ) = a 4 4 6 ()(x )(x 4)(x ) ()(x a)(x a)(x a ) ()(x )(x )(x ) (4)(a b)(a ab b )(a 6 a b b 6 ) (5)(x )(x 4 6)(x )(x 4) 00 ()x 6 x ()y 4 y ()(a b) (a b) ()x 6 x =x 8 ()y 4 y=y 5 ()(a b) (a b) =(a b) 5 ()a a 5 a ()x x 5 x ()a a 5 a=a 9 ()x x 5 x =x 9 () a a () x x () x ( x) ( x 5 ) () a a = a 5 5 ( ) x x = x x = x 6 () x ( x) ( x 5 ) x x x 5 = x 8 0 ()a 5 a 5 a 5 ()a 5 a 5 a 5 ()a 5 a 5 a 5 =6a 5 ()a 5 a 5 a 5 a 5 a 5 a 5 =6a 5 0 5 ()a a =a a a a 6 ()(a ) =a 5 (a ) =a =a 6

()ab 4a bc=a b 4 ab 4a bc a b 4 c (4)(x y) (6x y)=x y (x y) (6x y)=x 4 y (5)( x) 4 = x 4 ( x) 4 =( ) 4 x 4 =x 4 0 6 () () () ( x )( x x )= x 6x 9x 4 (4) (5) (6) 0 04 a m a n = a m n (a 0) 0 = = = 5 = 5 8 = a = m a (a 0 m m ) 0.00006 =.6 =.6 0 5 0 5 0.000. 0 4 0.00008=.8 0 5 5 m n (m 0 n 0) 0.000 0.00000 0.000 0.000 0.0005 0.000000056 0.00 0.00008 45.7608 05 0 0 = 00 = 0.0 0 = = 0.0 0 = 00 000 = 0.00 0 =0.0

a 0 m m m 00=0 000=0 4 ()4 0 5 ().0 0 4 ()600000000 () 0.0000008 () 00= 000= ()0.= 0.0= 0.00= 06 ( ) ( ) 4 5 ( x y ) ( x y ) 5 5 5(m n) 5(m n) 48a n b n c ( 6a n b n c) 4 5 5 4 (0.5a b a b a b ) ( 0.5a b ) 6 07 ( a b) 7 (a b) ( a b) 7 (a b) = (a b) 5 a b= (a b) ( a b) 7 (a b) [ (a b)] 7 (a b) = ( ) 7 (a b) 7 (a b) (a b) 7 (a b) (a b) 7 (a b) 5 (m n) 4 (n m) (a b) 5 (b a)

[ ]

08 09 ( ) A B C 0

AC BC=AB AB BC=AC AB AC=BC 4 a b b=a

l 5 4 AOB OC AOB AOC= BOC AOC = AOB BOC = AOB AOB= AOC AOB= BOC AOB O 6 7 9 5 4 7 9 5 4=7 4 9 4 5 4=48 6 0 =48 56 0 =49 56 0 9 4 7 8 4 55 7 8 4 55 4= =80 80 7 4=07 4=5 =80 80 8 4=08 4=5

55 7 8 4= 5 5 0 5 7 9 56 8 5 0 47 5 9 58 79 6 6 4 5 7 4 8 7 58 6 8 7 0 60 60 60 60 = 0 = 6 60 60 n n = 0 n 60 m m = 6 m 60 0 0 60 0 0 60 0 = 0 6 0 = 0 00 60 60 = 0 4 5 8 = 60 = 60 = ( 60 ) = ( 60 ) 8 4 8 8 8 4 = 8 4 ( ) = 8 4. 60 4. = 8 ( ) = 8405. 60 4.8 4.8 =4 0.8 60 =4 49. =4 49 0. 60

=4 49 =4 49 0.6 7.07 56. 47.5 4 6 5 7 8 4 4 76 54 54 5 4 5 6 5 9 6 n n n( n ) l A B C D E F l AOB OC OD OE O AOB 5 0 =90 =80 =90 =80 A 90 A 80 A=67 7 A A OC AB O AOC

BOC= OE OF AOC BOC OE OF 80 6 O AB CO DO AOC=40 BOD 7 AB CD O OE AOC AOE=0 BOC 8 AB CD O OE AB O BOD=5 EOC 4 9 AB CD EF O AOC = 45 DOF = AOC AOD EOD BOE 0 O AB OD OE AOC BOC OD OE

AOC BOC=80 DOC = AOC EOC = BOC DOC EOC=80 DOC EOC=90 DOE=90 OD OE 0 60 45 90 0 45 60 90 5 5 5 0 75 5 05 5 05 4 5

0 90 58 0 AOB OC AOC =90 4 0 5 6 7

6 75 AB DC B=75 DCB=05 75 7 8 F

4 4 Z 5 5 6 C 6 7 A B C D 8 AD EF EF BC AD BC 9 0

9 AB CD B= () AD BC () ( 9) A B=80 B BCD=80 ( 0) BE ABC CBF= CFB=65 EDF=50 BC AE ( ) COF C=80 C= B AB EF 4 ( ) AB CD AD BC =50 =0 4 6 6 4

() () () A= C AD BC AB CD ( 4) ABC=90 = DCA= CAB CD ACE ( 5) AB CD = BEF= EFC 4 ( 6) B= D AB DF BC DE ( 7) C D=80 B=90 AD AB ( 8) EF AB = CD AB

( 9) AC BC C ACD= CDE DE BC 4 ( 0) AC BD AE BE CAB ABD AE BE 4 AB CD O( ) ( ) AB CD EF O( ) ( ) A l B l ( 4)AB CD O( ) ( 5) AB C BC=AB D AD=AB () AB A B () l A CD l O () OA (4) AB C CD AB (5)O AB O CD AB (6) AB CD EF

(7) l P l PQ 5 6 D E F AB BC AC DE AC FE AB DEF= A DE AC( ) A= ( ) FE AB( ) DEF= ( ) DEF= A( ) DEF A DEF A ( 7) EF ABC A EF BC BAC B C=80 ( 8) AB CD EF AB CD M N MG NH EMA ENC MG NH ( 9) =85 =85 =5 4

5 6 () () () 80 (4) () () () (4)n n 7 500000 500000 =000000( ) 0 8

AB = AB C BC = AB E AB F BC EF= 9 () () () ( ) ( 0) BAD= BCD AE CF BAD BCD AD BC AE CF AE CF BC = BAD= BCD AE CF BAD BCD( ) = BAD = BCD( ) = ( ) AD BC( ) = EAD = BAD = ( ) = ( ) AE CF( ) ( ) B BED D=60 AB CD AB CD

AB CD E EF AB B BEF=80 ( ) B BED D=60 ( ) FED D=80 ( ) EF CD( ) AB CD( ) ( ) ABCD AD BC A= C AB CD ( ) BED= B D AB CD ( 4) OE DOF OG AOF B=90 AB OG 40 () =90 ( ) = ( ) () = ( ) AB CD ( 5) AD BC A= C AB CD AD BC( ) A= CBE( ) A= C( ) C= CBE( AB CD )

AD BC( ) A= CBE( ) ABC CBE=80 ( ) A= C( ) ABC C=80 ( ) AB CD( ) BC DC AD BC( ) = ( ) = C = C( ) A= C( ) = A( ) AD BC( ) A= ( ) = ( ) AB CD( ) 4 ( 6) ( 7) OB AOC ( 8) = ( ) BOC= BOC( ) DOB= AOC ( 9) = ( ) BOC= BOC( ) DOB= AOC 4

4 5 () 90 () 90 ( ) ( ) 80 AOB 60 COB 0 OA OC 4 5 44 ( ) ( ) AB CD AB CD AB CD O ( ) 45

46 47 ( 40) AB CD O AOC BOD AOD BOC AOC AOD 80 BOC AOD 80 ( ) AOC BOD( ) AOD BOC

( ) ( 60 00 ) ( 0 ) 5 5 6 (.4).5 4 a a 0 5 6 4 7 8 6580000 9.45 0 4.7 96800 x 0 x 5 x 4 5 5 6 4 () 4 m ()x 4 ( A B C D ) 5 [ ] A B C D 6 0. [ ] A B C D 7 [ ] A B C a D 8 [ ] A 6b B a 4 7 C D 0 c 9 a b [ ] A a c b B a b c

C a c b D a c b 0 n (n ) [ ] A n 4n B 4n 6n C n n 4 D n n ( ) 0.5 ( 8 ) a b a b 5 4 a b 8 5 x y x y (6 7 0 ) 6 8 7 ( 8) ( 7) 8 6 4 4 9 9 4 0 0 ( ) ( ) ( ) ( ) 0 ( ) 7 5 7 + 90 9 6 4 8 99 ( 6) 4 ( 0.5) 4 4 0 8 ( ) ( 4) ( ) 5 5 0. ( ) 5 6 [( ) ( 5) ] [( ) ( 5)] 4 7 7 0.5 5 5 4 (8 4 9 40 8 ) 8 a 7 b 9 c 6 a ()a + c b 6 ()c + a + 9 x y z 4 x y xy a + b + ab 40 a b a ab + b ( 9 ) 4 0 ( )

5.7 5.74 5.70 5.76 5.80 5.75 5.77 5.79 5.74 5.7 4 b () () b 5 4 a b c a b c b a

( ) ( 60 00 ) ( 0 ) [ (.75)] 4 5 5 5 a 6 ab 0 0 b 4 5 7 8 ( ) 4 9 0.5 0 4 4 ( 0 ) [ ] A B C D [ ] A B C D [ ] A B C D a 4 b 0 a b b [ ] A B C 0 D 5 [ ] A B ( ) C ( ) D ( ) ( 0 ) 6 000 7 00000 8 9000 9 70 0 8700000 50090000 9000 0000000 4 960000 5 456000

( 45 ) 6 ( 6.07) ( 48.5) 7 ( 4) 9 7 9 8 + 4 9 0 ( 7) 5 0 ( 999) 65 0 ( 998) 9 8 ( 5) 9 ( 0.8) ( 7.) (.5) 4 6 5 + 9 6 5 ( 5) 8 ( ) 5 6 5 6 6 7 ( 8) 4 ( 6) 4 9 8 7 0 6 9 ( ) 40 + ( 0 ) 4 a b c 5 () a + c a + b ac () () b b (4) a b a + c (5) c c b (5 ) 4 0 ( ).65.68.7.7.69.70.67.7.7.6 0

( ) ( 60 00 ) ( 0 ) t n x 0 x 4 5 6 ( ) a + 7 a 0 8 a 5a 9 a b a b 0 x 4kx 0 k x y 5x y 7xy x 4 x x 5 x 5 4 x 5 x x 5 ax b 0(a ) ( 8 ) 6 4 x y 5 5 0 y x 0 xy x [ ] A B C D 7 m n A n m B A 4B [ ] A 6m 8n 4 B 0m 8n 4 C 4m 8n 4 D 0m 8n 4 5y 7 8 = 6 [ ] 8 A y B y 5 C y D y 5 9 y (a y) a (y a) [ ] A 6a B 6a

C a D a a + a 0 a 4 7 [ ] A B 0 C D 5 0.5 7 [ ] A B 0.5 C D 7 ( 8 ) 5x 80 (x ) (4x ) 9( x) 5 4 x 5 = x 5 0.5x 0.7 6.5.6x y 4 y 6 y + = + 5 05. x ( x + ) 04x 8 7 45 =... 0. 5 06. ( ) 8 5x 7x x x 5 9 (xy 5x ) 8xy (xy 4x ) 0 (x y) (y z) (z x) x y xy xy x y xy xy ( 6 ) x x y x y + + x y x x x x + 7 5 ( 4 6 ) 4 0 050 0 50 0 5 450 65 85 () () 0

6 00 5 4 7 7. 5

( ) ( 60 00 ) ( 0 ) 5 ( ) x 5 x 4 8 5 x 6 x 6 69000 7.5 8 x 5 9 9x y 6 z x y n z n 0 x (x k) 8 k ( 8 ) A B A B [ ] A B C D [ ] A a b a b B ( a ) C x x 5x 6 x 7 x D n 0 8 6 x [ ] A x x B x x x C x x D x 4 [ ] A x 0 B x (x 7) 6 C (x )(x ) 0 D (x )(x ) 0 5 a b [ ] A 4a 6b B a b C 8a b D 6a 4b 6 [ ] A y 8 B 8 C 8 D y x 8

( ) ( ) x x 7 + = ( ) 8 (x y ) (0x 6y ) 9 [(x 4) (x )] 0 x (x x ) ( 0 x x ) (x y x ) (8x y x ) x y ( 6 ) x x + = x x 6( ) x ( ) x x + (x 5x 5) x x 6x 5x 5( ) x 6x x 5x 5( ) 5x x 4( ) (4 5 6 9 4 ) 4 ( x) 4 5 5( x) (4x 5) x 4x + 6 = 7 9 4 ( x + ) ( x ) = 8 [ (x )] 0. 4 0 9 x +. 0. 0 0. x + = x 0. 5 0. 0 ( 5 0 ) 0 ( x x x ) (5x x 4x ) x S (a b)h a b S 40 h ( 4 5 9 ) x x m n 0 4 m n c d a b a a b cd a a

( 60 00 ) ( 0 ) x y 0 x y x 4y 6 x m 5y n m 7 m n 4 x y 6 x x 5 y kx b k y y 6 x x 4 7 a 0 b 0 c 0 ab c 0 8 ax x (a 0) 9 6x x 0 x x 7 4k k ( 4 0 ) x y 4 [ ] A B C D x ax by a y ax by 5 [ ] A B C D 4x y x y k kx (k )y [ ] A 9 B 0 C D 4 [ ] A x 5 B x 5 C x 8 x 4 D 40 x 8 5

[ ] A B C D ( 5 5 ) x 7y 8 6 x 8y 0 (x ) y 5 7 5(y ) (x 5) x z 4 8 z y x y z ( 5 5 ) + x x 9 x 0 5 4x +. + 8 x + 5 x 4 ( 5 0 ) x 5y m m x 7y m 8 x y x y y 4 y x 4 A B 9 B 55 8 4 A.5 A B 5 80 4

( 60 00 ) ( 0 ) l l () 4 AB M AB N AM MN 5 () AOB OC AOB OD AOC AOD 6 () AOB BOC COD AOB 0 BOD 7 A B 65 B A 8 5 8 9 4 0 0 ( 4 40 ) [ ] A AB C BC AB C EF B AB C C A B C D AB C AC AB C BC AB AB D AD AB DC AB [ ] A B C 4 D 5

[ ] A B C D 4 4 [ ] A B C D 5 90 [ ] A B C D 6 [ ] A 60 B 90 C 0 D 7 7 50 [ ] A 70 0 B 60 0 C 80 0 D 8 (5) AB CD O AOE 90 EOD [ ] A BOD B BOD BOC C BOD AOE D BOD AOC 9 [ ] A B C D AB BA

0 [ ] A 75 5 65 B 60 0 0 C 50 0 0 D 70 0 0 ( 4 7 ) () AB CD F () m n M A m n () a A b B ( 4 4 5 9 5 ) [80 (8 4 4 7 45 )] 6 4 5 5 AB AB C BC AB D AC DC AB 6 00 7 (6) AOB 50 AOC BOD 90 COD 8 9 A 70 00 B B 40 50 C ( ) A C ( )

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