题目内容
计算:
(1)﹣12﹣|0.5﹣
|÷
×[﹣2﹣(﹣3)2];
(2)先化简,再求值:2(x2y+xy2)﹣2(x2y﹣x)﹣2xy2﹣2y的值,其中x=﹣2,y=2.
(1)﹣12﹣|0.5﹣
(2)先化简,再求值:2(x2y+xy2)﹣2(x2y﹣x)﹣2xy2﹣2y的值,其中x=﹣2,y=2.
解:(1)原式=﹣1﹣
×3×(﹣2﹣9)
=﹣1﹣
×3×(﹣11)
=﹣1+
=
;
(2)原式=2x2y+2xy2﹣2x2y+2x﹣2xy2﹣2y
=2x﹣2y;
当x=﹣2,y=2时,
原式=2×(﹣2)﹣2×2=﹣8.
=﹣1﹣
=﹣1+
=
(2)原式=2x2y+2xy2﹣2x2y+2x﹣2xy2﹣2y
=2x﹣2y;
当x=﹣2,y=2时,
原式=2×(﹣2)﹣2×2=﹣8.
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