7x^2-20x-75=0

Solution for 7x^2-20x-75=0 equation:

7x^2-20x-75=0

a = 7; b = -20; c = -75;
Δ = b2-4ac
Δ = -202-4·7·(-75)
Δ = 2500
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2500}=50$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-50}{2*7}=\frac{-30}{14}
=-2+1/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+50}{2*7}=\frac{70}{14}
=5
$