25x^2+20x-7=0

Solution for 25x^2+20x-7=0 equation:

25x^2+20x-7=0

a = 25; b = 20; c = -7;
Δ = b2-4ac
Δ = 202-4·25·(-7)
Δ = 1100
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:

$\sqrt{\Delta}=\sqrt{1100}=\sqrt{100*11}=\sqrt{100}*\sqrt{11}=10\sqrt{11}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-10\sqrt{11}}{2*25}=\frac{-20-10\sqrt{11}}{50}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+10\sqrt{11}}{2*25}=\frac{-20+10\sqrt{11}}{50}
$