Question

What two numbers add to -8 and multiply to 8??

Answer 1

$a+b=-8\\ ab=8\\\\ a=-8-b\\ ab=8\\\\ (-8-b)b=8\\ -8b-b^2-8=0\\ b^2+8b+8=0\\ b^2+8b+16=8\\ (b+4)^2=8\\ b+4 =-\sqrt8 \vee b+4=\sqrt8\\ b=-4-2\sqrt2 \vee b=-4+2\sqrt2\\\\ a=-8-(-4-2\sqrt2) \vee a=-8-(-4+2\sqrt2)\\ a=-8+4+2\sqrt2 \vee a=-8+4-2\sqrt2\\ a=-4+2\sqrt2 \ve a=-4-2\sqrt2$

$-4+2\sqrt2\text { and}-4-2\sqrt2$