5x2+4x=57

Solution for 5x2+4x=57 equation:

5x^2+4x=57

We move all terms to the left:

5x^2+4x-(57)=0

a = 5; b = 4; c = -57;
Δ = b2-4ac
Δ = 42-4·5·(-57)
Δ = 1156
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1156}=34$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-34}{2*5}=\frac{-38}{10}
=-3+4/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+34}{2*5}=\frac{30}{10}
=3
$