X2+72x-225=0

Solution for X2+72x-225=0 equation:

X2+72X-225=0

We add all the numbers together, and all the variables

X^2+72X-225=0

a = 1; b = 72; c = -225;
Δ = b2-4ac
Δ = 722-4·1·(-225)
Δ = 6084
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6084}=78$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(72)-78}{2*1}=\frac{-150}{2}
=-75
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+78}{2*1}=\frac{6}{2}
=3
$