Question

若(y+2)²+x²-6x=-9,则x+y的值是

Answer 1

若(y+2)²+x²-6x=-9,则x+y的值是1

若(y+2)²+x²-6x=-9,

则(y+2)²+(x²-6x+9)=0

(y+2)²+(x-3)²=0

y+2=0 y=-2

x-3=0 x=3

x+y=3-2=1