-3x2-15x=13

Solution for -3x2-15x=13 equation:

-3x^2-15x=13

We move all terms to the left:

-3x^2-15x-(13)=0

a = -3; b = -15; c = -13;
Δ = b2-4ac
Δ = -152-4·(-3)·(-13)
Δ = 69
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{69}}{2*-3}=\frac{15-\sqrt{69}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+\sqrt{69}}{2*-3}=\frac{15+\sqrt{69}}{-6}
$