2x(3x+25)=90

Solution for 2x(3x+25)=90 equation:

2x(3x+25)=90

We move all terms to the left:

2x(3x+25)-(90)=0

We multiply parentheses

6x^2+50x-90=0

a = 6; b = 50; c = -90;
Δ = b2-4ac
Δ = 502-4·6·(-90)
Δ = 4660
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:

$\sqrt{\Delta}=\sqrt{4660}=\sqrt{4*1165}=\sqrt{4}*\sqrt{1165}=2\sqrt{1165}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(50)-2\sqrt{1165}}{2*6}=\frac{-50-2\sqrt{1165}}{12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(50)+2\sqrt{1165}}{2*6}=\frac{-50+2\sqrt{1165}}{12}
$