Question

Y = (-X)(-X) + 2 X + 4

X + Y = 4

Answer 1

$y=(-x)(-x)+2x+4\\ x+y=4\\\\ y=x^2+2x+4\\ y=-x+4\\\\ -x+4=x^2+2x+4\\ x^2+3x=0\\ x(x+3)=0\\ x=0 \vee x=-3\\\\ y=-0+4 \vee y=-(-3)+4\\ y=4 \vee y=7\\\\ x=0,y=4\\ x=-3,y=7$