10b^2-6b-28=0

Solution for 10b^2-6b-28=0 equation:

10b^2-6b-28=0

a = 10; b = -6; c = -28;
Δ = b2-4ac
Δ = -62-4·10·(-28)
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{-(-6)-34}{2*10}=\frac{-28}{20}
=-1+2/5
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+34}{2*10}=\frac{40}{20}
=2
$