1 ( 1) 7-3x-4x2+4x-8x2-15 (2) 2(2a2-9b)-3(- 4a2+b) (3) 8x2-[-3x-(2x2-7x-5)+3]+4x (4) )312(65aa (5) baba)5(2 (6) - 32009)214(2)2(yxyx (7) - 12)1(32nmm (8) )(4)()(3222222yzzyyx (9)1}1]1)1([{2222xxxx 2 ( 10) (2x-3y)+(5x+4y) ( 11) (8a-7b)-(4a-5b) ( 12) a-(2a+b)+2(a-2b) ( 13) 3(5x+4)-(3x-5) ( 14) x+[ x+(-2x-4y)] ( 15) (a+4b)- (3a-6b) ( 16)3x2-1-2x-5+3x-x2 (17) (a+4b)- (3a-6b) (18)4x+2y— 5x— y ( 19)—3ab+7— 2a2— 9ab— 3 3 ( 20) 7x2-2x+3x-7x2 ( 21) -0
8a2b-6ab-1
2a2b+5ab+a2b ( 22)222baba43ab21a32 ( 23) 6x2y+2xy-3x2y2-7x-5yx-4y2x2-6x 2y ( 24) 8x+ 2y+ 2( 5x- 2y) ( 25) 3a-(4b- 2a+ 1) ( 26) 7m+ 3( m+ 2n) ( 27)(x2- y2)-4( 2x2- 3y2) ( 28)-4x+ 3( 31 x- 2) ( 29) 5(2x-7y)-3 (4x-3y) 4 ( 30)baba22212 ( 31)bababa2222132 ( 32)322223babbaabbaa ( 33)5253432222xyyxxyy