X^2+90x=7925

Solution for X^2+90x=7925 equation:

X^2+90X=7925

We move all terms to the left:

X^2+90X-(7925)=0

a = 1; b = 90; c = -7925;
Δ = b2-4ac
Δ = 902-4·1·(-7925)
Δ = 39800
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:

$\sqrt{\Delta}=\sqrt{39800}=\sqrt{100*398}=\sqrt{100}*\sqrt{398}=10\sqrt{398}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(90)-10\sqrt{398}}{2*1}=\frac{-90-10\sqrt{398}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(90)+10\sqrt{398}}{2*1}=\frac{-90+10\sqrt{398}}{2}
$