X(x+65)=315

Solution for X(x+65)=315 equation:

X(X+65)=315

We move all terms to the left:

X(X+65)-(315)=0

We multiply parentheses

X^2+65X-315=0

a = 1; b = 65; c = -315;
Δ = b2-4ac
Δ = 652-4·1·(-315)
Δ = 5485
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(65)-\sqrt{5485}}{2*1}=\frac{-65-\sqrt{5485}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(65)+\sqrt{5485}}{2*1}=\frac{-65+\sqrt{5485}}{2}
$