e^2+7e=10

Solution for e^2+7e=10 equation:

e^2+7e=10

We move all terms to the left:

e^2+7e-(10)=0

a = 1; b = 7; c = -10;
Δ = b2-4ac
Δ = 72-4·1·(-10)
Δ = 89
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$e_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$e_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$e_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(7)-\sqrt{89}}{2*1}=\frac{-7-\sqrt{89}}{2}
$
$e_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+\sqrt{89}}{2*1}=\frac{-7+\sqrt{89}}{2}
$