4x^2-26x=90

Solution for 4x^2-26x=90 equation:

4x^2-26x=90

We move all terms to the left:

4x^2-26x-(90)=0

a = 4; b = -26; c = -90;
Δ = b2-4ac
Δ = -262-4·4·(-90)
Δ = 2116
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2116}=46$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-46}{2*4}=\frac{-20}{8}
=-2+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+46}{2*4}=\frac{72}{8}
=9
$