X2+9x=7

Solution for X2+9x=7 equation:

X2+9X=7

We move all terms to the left:

X2+9X-(7)=0

We add all the numbers together, and all the variables

X^2+9X-7=0

a = 1; b = 9; c = -7;
Δ = b2-4ac
Δ = 92-4·1·(-7)
Δ = 109
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{-(9)-\sqrt{109}}{2*1}=\frac{-9-\sqrt{109}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{109}}{2*1}=\frac{-9+\sqrt{109}}{2}
$