240=5x^2-2x

Solution for 240=5x^2-2x equation:

240=5x^2-2x

We move all terms to the left:

240-(5x^2-2x)=0

We get rid of parentheses

-5x^2+2x+240=0

a = -5; b = 2; c = +240;
Δ = b2-4ac
Δ = 22-4·(-5)·240
Δ = 4804
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:

$\sqrt{\Delta}=\sqrt{4804}=\sqrt{4*1201}=\sqrt{4}*\sqrt{1201}=2\sqrt{1201}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{1201}}{2*-5}=\frac{-2-2\sqrt{1201}}{-10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{1201}}{2*-5}=\frac{-2+2\sqrt{1201}}{-10}
$