d^2+11d-12=0

Solution for d^2+11d-12=0 equation:

d^2+11d-12=0

a = 1; b = 11; c = -12;
Δ = b2-4ac
Δ = 112-4·1·(-12)
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(11)-13}{2*1}=\frac{-24}{2}
=-12
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+13}{2*1}=\frac{2}{2}
=1
$