15x+4x^2=30

Solution for 15x+4x^2=30 equation:

15x+4x^2=30

We move all terms to the left:

15x+4x^2-(30)=0

a = 4; b = 15; c = -30;
Δ = b2-4ac
Δ = 152-4·4·(-30)
Δ = 705
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{-(15)-\sqrt{705}}{2*4}=\frac{-15-\sqrt{705}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+\sqrt{705}}{2*4}=\frac{-15+\sqrt{705}}{8}
$