88=2x(x+9)

Solution for 88=2x(x+9) equation:

88=2x(x+9)

We move all terms to the left:

88-(2x(x+9))=0


We calculate terms in parentheses: -(2x(x+9)), so:

2x(x+9)

We multiply parentheses

2x^2+18x

Back to the equation:

-(2x^2+18x)


We get rid of parentheses

-2x^2-18x+88=0

a = -2; b = -18; c = +88;
Δ = b2-4ac
Δ = -182-4·(-2)·88
Δ = 1028
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:

$\sqrt{\Delta}=\sqrt{1028}=\sqrt{4*257}=\sqrt{4}*\sqrt{257}=2\sqrt{257}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-2\sqrt{257}}{2*-2}=\frac{18-2\sqrt{257}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+2\sqrt{257}}{2*-2}=\frac{18+2\sqrt{257}}{-4}
$