已知,a－2的绝对值与（b＋1）²互为相反数,求5a²b－2ab²＋3ab的值.

已知,a－2的绝对值与（b＋1）²互为相反数,求5a²b－2ab²＋3ab的值.
已知,a－2的绝对值与（b＋1）²互为相反数,求5a²b－2ab²＋3ab的值.

已知,a－2的绝对值与（b＋1）²互为相反数,求5a²b－2ab²＋3ab的值.
a－2的绝对值与（b＋1）²互为相反数,
则a－2的绝对值+（b＋1）²=0
则a-2=0,b+1=0
a=2,b=-1
5a²b－2ab²＋3ab
=5×2²×(-1)-2×2×(-1)²+3×2×(-1)
=-20-4-6
=-30

a－2的绝对值与（b＋1）²互为相反数
所以
|a-2|=（b+1）²=0
a=2
b=-1
5a²b－2ab²＋3ab
=-5×4-2×2-3×2
=-20-4-6
=-30

a－2的绝对值与（b＋1）²互为相反数，二者均为非负数，所以
a-2=0 a=2
b+1=0 b=--1
代入求值
-20-4-6=-30