X2=-2x+87

Solution for X2=-2x+87 equation:

X2=-2X+87

We move all terms to the left:

X2-(-2X+87)=0

We add all the numbers together, and all the variables

X^2-(-2X+87)=0

We get rid of parentheses

X^2+2X-87=0

a = 1; b = 2; c = -87;
Δ = b2-4ac
Δ = 22-4·1·(-87)
Δ = 352
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{352}=\sqrt{16*22}=\sqrt{16}*\sqrt{22}=4\sqrt{22}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-4\sqrt{22}}{2*1}=\frac{-2-4\sqrt{22}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+4\sqrt{22}}{2*1}=\frac{-2+4\sqrt{22}}{2}
$