15b^2-23b+4=0

Solution for 15b^2-23b+4=0 equation:

15b^2-23b+4=0

a = 15; b = -23; c = +4;
Δ = b2-4ac
Δ = -232-4·15·4
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-23)-17}{2*15}=\frac{6}{30}
=1/5
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-23)+17}{2*15}=\frac{40}{30}
=1+1/3
$