Question

已知丨x-y+1丨与x²+8x+16互为相反数,则x²+2xy+y²＝？

急。。。。。。。。。。。。。。。。。。

Answer 1

丨源型x-y+1丨与x²+8x+16互为相反数,
所以
丨x-y+1丨+x²+8x+16=0
即丨x-y+1丨+（x+4）²=0
所以
x-y+1=0,x+4=0
即
x=-4
y=-3
所以雹握猜
x²+2xy+y²
＝皮键（x+y）²
=(-3-4)²
=49

Answer 2

丨x-y+1丨与x²圆拦+8x+16互为判并相反橘冲胡数
x-y+1=0
x^2+8x+16=0=(x+4)^2
x=-4,y=-3
x²+2xy+y²＝(x+y)²=(-4-3)²=49