X^2+11x+18=7

Solution for X^2+11x+18=7 equation:

X^2+11X+18=7

We move all terms to the left:

X^2+11X+18-(7)=0

We add all the numbers together, and all the variables

X^2+11X+11=0

a = 1; b = 11; c = +11;
Δ = b2-4ac
Δ = 112-4·1·11
Δ = 77
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{77}}{2*1}=\frac{-11-\sqrt{77}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+\sqrt{77}}{2*1}=\frac{-11+\sqrt{77}}{2}
$