150=1.2v+.06v^2

Solution for 150=1.2v+.06v^2 equation:

150=1.2v+.06v^2

We move all terms to the left:

150-(1.2v+.06v^2)=0

We get rid of parentheses

-.06v^2-1.2v+150=0

We add all the numbers together, and all the variables

-0.06v^2-1.2v+150=0

a = -0.06; b = -1.2; c = +150;
Δ = b2-4ac
Δ = -1.22-4·(-0.06)·150
Δ = 37.44
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{-(-1.2)-\sqrt{37.44}}{2*-0.06}=\frac{1.2-\sqrt{37.44}}{-0.12}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.2)+\sqrt{37.44}}{2*-0.06}=\frac{1.2+\sqrt{37.44}}{-0.12}
$