25x2+25x=15

Solution for 25x2+25x=15 equation:

25x^2+25x=15

We move all terms to the left:

25x^2+25x-(15)=0

a = 25; b = 25; c = -15;
Δ = b2-4ac
Δ = 252-4·25·(-15)
Δ = 2125
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:

$\sqrt{\Delta}=\sqrt{2125}=\sqrt{25*85}=\sqrt{25}*\sqrt{85}=5\sqrt{85}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-5\sqrt{85}}{2*25}=\frac{-25-5\sqrt{85}}{50}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+5\sqrt{85}}{2*25}=\frac{-25+5\sqrt{85}}{50}
$