4x^2+5x=18

Solution for 4x^2+5x=18 equation:

4x^2+5x=18

We move all terms to the left:

4x^2+5x-(18)=0

a = 4; b = 5; c = -18;
Δ = b2-4ac
Δ = 52-4·4·(-18)
Δ = 313
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-\sqrt{313}}{2*4}=\frac{-5-\sqrt{313}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+\sqrt{313}}{2*4}=\frac{-5+\sqrt{313}}{8}
$