1 合 并 同 类 项 、 去 括 号 试 题 1. 合 并 下 列 各 式 中 的 同 类 项 ( 1) 3x2-1-2x-5+3x-x2 ( 2) 4xy-3y2-3x2+xy-3xy-2x2-4y2 ( 3) -0.8a2b-6ab-1.2a2b+5ab+a2b ( 4)222baba43ab21a32 ( 5) 5(a-b)2-7(a-b)+3(a-b)2-9(a-b) ( 6) 3xn+1-4xn-1+ 12xn+1+ 32xn-1+5xn-2xn ( 7) 3a- ( 4b- 2a+ 1) ( 8) x- [ (3x+ 1)- (4- x)] (9)- 4x+ 3(31 x- 2) ( 10) (3x-5y)-(6x+7y)+(9x-2y) ( 11) 2a-[3b-5a-(3a-5b)] ( 12)323722aaaa ( 13) 5(43 )( 3)abaab ( 14)222(25)(32)2( 41)aaa 2 ( 15)(531)(21)xxyxy ( 16)232aaba ( 17) 8(2 )4(3)2xyxyzz ( 18)23(2)2ababaa ( 19) 8x+ 2y+ 2( 5x- 2y) ( 20)( x2- y2) - 4( 2x2- 3y2) ( 21) - 3(2x3y- 3x2y2+ 3xy3) ( 22)( - 4y+ 3) - (- 5y- 2) + 3y ( 23)( 6 x2- x+ 3) - 2(4x2+ 6x- 2 ( 24)222234(3)xxxxx ( 25) 11(46 )3( 22 )32aabccb ( 26)(43 )(3)()5xyyxxyx ( 27)22121232aabab ( 28) 2-[2(x+3y)-3(x-2y)] ( 29)( 2m-3) +m-( 3m-2) ( 30) 3( 4x-2y) -3( -y+8x). 3 (31)(2x-3y)+(5x+4y) (32)(8a-7b)-(4a-5b) (33)a-(2a+b)+2(a-2b) (34)3(5x+4)-(3x-5) (35)(8x-3y)-(4x+3y-z)+2z (36)-5x2+(5x-8x2)-(-12x2+4x)+2 (37)2-(1+x)+(1+x+x2-x2) (38)3a2+a2-(2a2-2a)+(3a-a2) (39)2a-3b+[ 4a-(3a-b)] (40)3b-2c-[ -4a+(c+3b)] +c ( 41) x-( 3x-2) +( 2x-3) ( 42)( 3a2+a-5) -( 4-a+7a2) ( 43) x2+( -3x-2y+1) ( 44) x-( x2-x3+1) ( 45) 3a+4b-(2b+4a) ( 46) (2x-3y)-3(4x-2y) 4 (47)(2x-3y)+(5x+4y) (48)(8a-7b)-(4a-5b) (49)a-(2a+b)+2(a-2b) (50)3(5x+4)-(3x-5) (51)(8x-3y)-(4x+3y-z)+2z (52)-5x2+(5x-8x2)-(-12x2+4x)+2 (53)2-(1+x)+(1+x+x2-x2) (54)3a2+a2-(2a2-2a)+(3a-a2) (55)5a+ (3x- 3y- 4a) (56)3x- ( 4y- ...