11x^2+4x-15=0

Solution for 11x^2+4x-15=0 equation:

11x^2+4x-15=0

a = 11; b = 4; c = -15;
Δ = b2-4ac
Δ = 42-4·11·(-15)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-26}{2*11}=\frac{-30}{22}
=-1+4/11
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+26}{2*11}=\frac{22}{22}
=1
$