化简:(1)3x2-[7x-(4x-3)-2x2](2)(2xy-y)-(-y+yx)(3)5(a2b-3ab2)-2(a2b-7ab2)
题型:解答题难度:一般来源:不详
化简: (1)3x2-[7x-(4x-3)-2x2] (2)(2xy-y)-(-y+yx) (3)5(a2b-3ab2)-2(a2b-7ab2) |
答案
(1)原式=3x2-7x+4x-3+2x2 =(3+2)x2+(-7+4)x-3 =5x2-3x-3;
(2)原式=2xy-y+-y-yx =xy;
(3)原式=5a2b-15ab2-2a2b+14ab2 =(5-2)a2b-(15-14)ab2 =3a2b-ab2. |
举一反三
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