4x^2+3x=15

Solution for 4x^2+3x=15 equation:

4x^2+3x=15

We move all terms to the left:

4x^2+3x-(15)=0

a = 4; b = 3; c = -15;
Δ = b2-4ac
Δ = 32-4·4·(-15)
Δ = 249
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{-(3)-\sqrt{249}}{2*4}=\frac{-3-\sqrt{249}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{249}}{2*4}=\frac{-3+\sqrt{249}}{8}
$