q^2+25q=900

Solution for q^2+25q=900 equation:

q^2+25q=900

We move all terms to the left:

q^2+25q-(900)=0

a = 1; b = 25; c = -900;
Δ = b2-4ac
Δ = 252-4·1·(-900)
Δ = 4225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$q_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$q_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4225}=65$
$q_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-65}{2*1}=\frac{-90}{2}
=-45
$
$q_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+65}{2*1}=\frac{40}{2}
=20
$