若(3x-y+5)²+√2x-y+3=0,求x-y的值
问题描述:
若(3x-y+5)²+√2x-y+3=0,求x-y的值
答
(3x-y+5)²+√2x-y+3=0,
3x-y+5 =0 ①
2x-y+3 = 0 ②
①-② x+2 = 0
x = -2
y = 3x+5= -6+5= -1
x-y的值
= -2 +1
= -1