0=15x^2+88x+121

Solution for 0=15x^2+88x+121 equation:

0=15x^2+88x+121

We move all terms to the left:

0-(15x^2+88x+121)=0

We add all the numbers together, and all the variables

-(15x^2+88x+121)=0

We get rid of parentheses

-15x^2-88x-121=0

a = -15; b = -88; c = -121;
Δ = b2-4ac
Δ = -882-4·(-15)·(-121)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-88)-22}{2*-15}=\frac{66}{-30}
=-2+1/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-88)+22}{2*-15}=\frac{110}{-30}
=-3+2/3
$