4=2x^2-10x

Solution for 4=2x^2-10x equation:

4=2x^2-10x

We move all terms to the left:

4-(2x^2-10x)=0

We get rid of parentheses

-2x^2+10x+4=0

a = -2; b = 10; c = +4;
Δ = b2-4ac
Δ = 102-4·(-2)·4
Δ = 132
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:

$\sqrt{\Delta}=\sqrt{132}=\sqrt{4*33}=\sqrt{4}*\sqrt{33}=2\sqrt{33}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-2\sqrt{33}}{2*-2}=\frac{-10-2\sqrt{33}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+2\sqrt{33}}{2*-2}=\frac{-10+2\sqrt{33}}{-4}
$