(6+x)x=(7+5)5

Solution for (6+x)x=(7+5)5 equation:

(6+x)x=(7+5)5

We move all terms to the left:

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

We add all the numbers together, and all the variables

(x+6)x-(125)=0

We add all the numbers together, and all the variables

(x+6)x-125=0

We multiply parentheses

x^2+6x-125=0

a = 1; b = 6; c = -125;
Δ = b2-4ac
Δ = 62-4·1·(-125)
Δ = 536
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:

$\sqrt{\Delta}=\sqrt{536}=\sqrt{4*134}=\sqrt{4}*\sqrt{134}=2\sqrt{134}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-2\sqrt{134}}{2*1}=\frac{-6-2\sqrt{134}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+2\sqrt{134}}{2*1}=\frac{-6+2\sqrt{134}}{2}
$