7x^2-180x-900=0

Solution for 7x^2-180x-900=0 equation:

7x^2-180x-900=0

a = 7; b = -180; c = -900;
Δ = b2-4ac
Δ = -1802-4·7·(-900)
Δ = 57600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{57600}=240$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-180)-240}{2*7}=\frac{-60}{14}
=-4+2/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-180)+240}{2*7}=\frac{420}{14}
=30
$