X^2+7x=99

Solution for X^2+7x=99 equation:

X^2+7X=99

We move all terms to the left:

X^2+7X-(99)=0

a = 1; b = 7; c = -99;
Δ = b2-4ac
Δ = 72-4·1·(-99)
Δ = 445
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{-(7)-\sqrt{445}}{2*1}=\frac{-7-\sqrt{445}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+\sqrt{445}}{2*1}=\frac{-7+\sqrt{445}}{2}
$