3x^2+15x=528

Solution for 3x^2+15x=528 equation:

3x^2+15x=528

We move all terms to the left:

3x^2+15x-(528)=0

a = 3; b = 15; c = -528;
Δ = b2-4ac
Δ = 152-4·3·(-528)
Δ = 6561
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6561}=81$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-81}{2*3}=\frac{-96}{6}
=-16
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+81}{2*3}=\frac{66}{6}
=11
$