若/y+5/+(x-2)^2=0,求-3(2x-y)-[6x+2y-(10x-8y)]的值_数学解答

若/y+5/+(x-2)^2=0,求-3(2x-y)-[6x+2y-(10x-8y)]的值

人气：451 ℃　时间：2020-05-10 10:40:20

解答

因为绝对值大于等于0
y+5=0
y=-5
x-2=0
x=2
-6x+3y-(6x+2y-10x+8y)
=-6x+3y-(10y-4x)
=-6x+3y-10y+4x
=-2x-7y
将x=2 y=-5代入
=-4+35
=31