X2+15x-16=0

Solution for X2+15x-16=0 equation:

X2+15X-16=0

We add all the numbers together, and all the variables

X^2+15X-16=0

a = 1; b = 15; c = -16;
Δ = b2-4ac
Δ = 152-4·1·(-16)
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-17}{2*1}=\frac{-32}{2}
=-16
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+17}{2*1}=\frac{2}{2}
=1
$