X(60-2x)=30

Solution for X(60-2x)=30 equation:

X(60-2X)=30

We move all terms to the left:

X(60-2X)-(30)=0

We add all the numbers together, and all the variables

X(-2X+60)-30=0

We multiply parentheses

-2X^2+60X-30=0

a = -2; b = 60; c = -30;
Δ = b2-4ac
Δ = 602-4·(-2)·(-30)
Δ = 3360
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:

$\sqrt{\Delta}=\sqrt{3360}=\sqrt{16*210}=\sqrt{16}*\sqrt{210}=4\sqrt{210}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(60)-4\sqrt{210}}{2*-2}=\frac{-60-4\sqrt{210}}{-4}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(60)+4\sqrt{210}}{2*-2}=\frac{-60+4\sqrt{210}}{-4}
$