|3x+2y+3|+(5y+2x-9)^2=0,求3x-2y的值 (5y+2x-9)^2是(5y+2x-9)的平方.
问题描述:
|3x+2y+3|+(5y+2x-9)^2=0,求3x-2y的值 (5y+2x-9)^2是(5y+2x-9)的平方.
答
|3x+2y+3|+(5y+2x-9)^2=0
由于平方和绝对值都是非负数
要相加是0 必须同时为0
3x+2y+3 = 0
5y+2x-9=0
x=-3
y=3
3x-2y =-15