(X+6)x=315

Solution for (X+6)x=315 equation:

(X+6)X=315

We move all terms to the left:

(X+6)X-(315)=0

We multiply parentheses

X^2+6X-315=0

a = 1; b = 6; c = -315;
Δ = b2-4ac
Δ = 62-4·1·(-315)
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-36}{2*1}=\frac{-42}{2}
=-21
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+36}{2*1}=\frac{30}{2}
=15
$