6x(x+5)-5x=25

Solution for 6x(x+5)-5x=25 equation:

6x(x+5)-5x=25

We move all terms to the left:

6x(x+5)-5x-(25)=0

We add all the numbers together, and all the variables

-5x+6x(x+5)-25=0

We multiply parentheses

6x^2-5x+30x-25=0

We add all the numbers together, and all the variables

6x^2+25x-25=0

a = 6; b = 25; c = -25;
Δ = b2-4ac
Δ = 252-4·6·(-25)
Δ = 1225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1225}=35$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-35}{2*6}=\frac{-60}{12}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+35}{2*6}=\frac{10}{12}
=5/6
$