(2x)(x+5)=225

Solution for (2x)(x+5)=225 equation:

(2x)(x+5)=225

We move all terms to the left:

(2x)(x+5)-(225)=0

We multiply parentheses

2x^2+10x-225=0

a = 2; b = 10; c = -225;
Δ = b2-4ac
Δ = 102-4·2·(-225)
Δ = 1900
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:

$\sqrt{\Delta}=\sqrt{1900}=\sqrt{100*19}=\sqrt{100}*\sqrt{19}=10\sqrt{19}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-10\sqrt{19}}{2*2}=\frac{-10-10\sqrt{19}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+10\sqrt{19}}{2*2}=\frac{-10+10\sqrt{19}}{4}
$