15x2=4x+4

Solution for 15x2=4x+4 equation:

15x^2=4x+4

We move all terms to the left:

15x^2-(4x+4)=0

We get rid of parentheses

15x^2-4x-4=0

a = 15; b = -4; c = -4;
Δ = b2-4ac
Δ = -42-4·15·(-4)
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-16}{2*15}=\frac{-12}{30}
=-2/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+16}{2*15}=\frac{20}{30}
=2/3
$