15k2-7k=4

Solution for 15k2-7k=4 equation:

15k^2-7k=4

We move all terms to the left:

15k^2-7k-(4)=0

a = 15; b = -7; c = -4;
Δ = b2-4ac
Δ = -72-4·15·(-4)
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-17}{2*15}=\frac{-10}{30}
=-1/3
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+17}{2*15}=\frac{24}{30}
=4/5
$