(5x)(25x+30)=180

Solution for (5x)(25x+30)=180 equation:

(5x)(25x+30)=180

We move all terms to the left:

(5x)(25x+30)-(180)=0

We multiply parentheses

125x^2+150x-180=0

a = 125; b = 150; c = -180;
Δ = b2-4ac
Δ = 1502-4·125·(-180)
Δ = 112500
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:

$\sqrt{\Delta}=\sqrt{112500}=\sqrt{22500*5}=\sqrt{22500}*\sqrt{5}=150\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(150)-150\sqrt{5}}{2*125}=\frac{-150-150\sqrt{5}}{250}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(150)+150\sqrt{5}}{2*125}=\frac{-150+150\sqrt{5}}{250}
$