Question

i need help and i dont know how to do the work of it​

Answer 1

Answer:

Step-by-step explanation:

$xy=5, y=-2x-8$
Using substitution,

$x(-2x-8)=-5\\-2x^{2}-8x=-5\\2x^{2}+8x-5=0\\x=\frac{-8 \pm \sqrt{8^{2}-4(2)(-5)}}{4}\\x=\frac{-8 \pm \sqrt{104}}{4}\\x=-2 \pm \sqrt{13/2}$

So, if $x=-2+\sqrt{13/2}$, y=$-2(-2+\sqrt{13/2})-8=4-\sqrt{26}$

And if $x=-2-\sqrt{13/2}$, $y=-2(-2-\sqrt{13/2})=\sqrt{26}-4$