-18v=-v^2+88

Solution for -18v=-v^2+88 equation:

-18v=-v^2+88

We move all terms to the left:

-18v-(-v^2+88)=0

We get rid of parentheses

v^2-18v-88=0

a = 1; b = -18; c = -88;
Δ = b2-4ac
Δ = -182-4·1·(-88)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-26}{2*1}=\frac{-8}{2}
=-4
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+26}{2*1}=\frac{44}{2}
=22
$