-4b2-14b+60=0

Solution for -4b2-14b+60=0 equation:

-4b^2-14b+60=0

a = -4; b = -14; c = +60;
Δ = b2-4ac
Δ = -142-4·(-4)·60
Δ = 1156
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1156}=34$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-34}{2*-4}=\frac{-20}{-8}
=2+1/2
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+34}{2*-4}=\frac{48}{-8}
=-6
$