1.5=60x-20x^2

Solution for 1.5=60x-20x^2 equation:

1.5=60x-20x^2

We move all terms to the left:

1.5-(60x-20x^2)=0

We get rid of parentheses

20x^2-60x+1.5=0

a = 20; b = -60; c = +1.5;
Δ = b2-4ac
Δ = -602-4·20·1.5
Δ = 3480
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:

$\sqrt{\Delta}=\sqrt{3480}=\sqrt{4*870}=\sqrt{4}*\sqrt{870}=2\sqrt{870}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-2\sqrt{870}}{2*20}=\frac{60-2\sqrt{870}}{40}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+2\sqrt{870}}{2*20}=\frac{60+2\sqrt{870}}{40}
$