已知|x-y+1|与x^+8x+16互为相反数,求x^+2xy+y^的值.x^2+2xy+y^2

已知|x-y+1|与x^+8x+16互为相反数,求x^+2xy+y^的值.x^2+2xy+y^2
已知|x-y+1|与x^+8x+16互为相反数,求x^+2xy+y^的值.
x^2+2xy+y^2

已知|x-y+1|与x^+8x+16互为相反数,求x^+2xy+y^的值.x^2+2xy+y^2
由题意：

x-y+1=0
（x+4）²=0


所以：
x=-4
y=-3


所以：
x²+2xy+y²
=（x+y）²
=（-4-3）²
=49