X2-11x=-8

Solution for X2-11x=-8 equation:

X2-11X=-8

We move all terms to the left:

X2-11X-(-8)=0

We add all the numbers together, and all the variables

X^2-11X+8=0

a = 1; b = -11; c = +8;
Δ = b2-4ac
Δ = -112-4·1·8
Δ = 89
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-11)-\sqrt{89}}{2*1}=\frac{11-\sqrt{89}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-11)+\sqrt{89}}{2*1}=\frac{11+\sqrt{89}}{2}
$