(X)(x+15)=2625

Solution for (X)(x+15)=2625 equation:

(X)(X+15)=2625

We move all terms to the left:

(X)(X+15)-(2625)=0

We multiply parentheses

X^2+15X-2625=0

a = 1; b = 15; c = -2625;
Δ = b2-4ac
Δ = 152-4·1·(-2625)
Δ = 10725
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:

$\sqrt{\Delta}=\sqrt{10725}=\sqrt{25*429}=\sqrt{25}*\sqrt{429}=5\sqrt{429}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-5\sqrt{429}}{2*1}=\frac{-15-5\sqrt{429}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+5\sqrt{429}}{2*1}=\frac{-15+5\sqrt{429}}{2}
$