90x-7x^2+112=0

Solution for 90x-7x^2+112=0 equation:

90x-7x^2+112=0

a = -7; b = 90; c = +112;
Δ = b2-4ac
Δ = 902-4·(-7)·112
Δ = 11236
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{11236}=106$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(90)-106}{2*-7}=\frac{-196}{-14}
=+14
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(90)+106}{2*-7}=\frac{16}{-14}
=-1+1/7
$