题目

4x的平方y-{x的平方y-[3xy的平方-1/2(4x的平方y-8xy的平方)+x的平方y]}-5xy的平方 先化简 其中
x=-3/2 y=-1/3 再求值 直接说得数就行

提问时间：2020-10-27

答案

4x²y-{x²y-[3xy²-1/2(4x²y-8xy²)+x²y]}-5xy²
=4x²y-x²y+[3xy²-1/2(4x²y-8xy²)+x²y]-5xy²
=3x²y+3xy²-1/2(4x²y-8xy²)+x²y-5xy²
=4x²y-2x²y-2x²y+4xy²
=2x²y+2xy²
=2×9/4×(-1/3)+2×(-3/2)×(1/9)
=-3/2-1/3
=-11/6