10(x+5)x=-7

Solution for 10(x+5)x=-7 equation:

10(x+5)x=-7

We move all terms to the left:

10(x+5)x-(-7)=0

We add all the numbers together, and all the variables

10(x+5)x+7=0

We multiply parentheses

10x^2+50x+7=0

a = 10; b = 50; c = +7;
Δ = b2-4ac
Δ = 502-4·10·7
Δ = 2220
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:

$\sqrt{\Delta}=\sqrt{2220}=\sqrt{4*555}=\sqrt{4}*\sqrt{555}=2\sqrt{555}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(50)-2\sqrt{555}}{2*10}=\frac{-50-2\sqrt{555}}{20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(50)+2\sqrt{555}}{2*10}=\frac{-50+2\sqrt{555}}{20}
$