v2+19v=90=0

Solution for v2+19v=90=0 equation:

v2+19v=90=0

We move all terms to the left:

v2+19v-(90)=0

We add all the numbers together, and all the variables

v^2+19v-90=0

a = 1; b = 19; c = -90;
Δ = b2-4ac
Δ = 192-4·1·(-90)
Δ = 721
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19)-\sqrt{721}}{2*1}=\frac{-19-\sqrt{721}}{2}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19)+\sqrt{721}}{2*1}=\frac{-19+\sqrt{721}}{2}
$