5x^2-4x=28

Solution for 5x^2-4x=28 equation:

5x^2-4x=28

We move all terms to the left:

5x^2-4x-(28)=0

a = 5; b = -4; c = -28;
Δ = b2-4ac
Δ = -42-4·5·(-28)
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-24}{2*5}=\frac{-20}{10}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+24}{2*5}=\frac{28}{10}
=2+4/5
$