若2x+1的绝对值+根号y+2=0,则立方根号5x^3-y^2=?

题目

若2x+1的绝对值+根号y+2=0,则立方根号5x^3-y^2=?

答案

2x+1的绝对值+根号y+2=0,
则2x+1=0 y+2=0
则x= -1/2 y= -2
5x^3-y^2
=5×（-1/2）³-（-2）²
=5/8-4
= -27/8