-3-13.8=-8x(6x+1)

Solution for -3-13.8=-8x(6x+1) equation:

-3-13.8=-8x(6x+1)

We move all terms to the left:

-3-13.8-(-8x(6x+1))=0

We add all the numbers together, and all the variables

-(-8x(6x+1))-16.8=0


We calculate terms in parentheses: -(-8x(6x+1)), so:

-8x(6x+1)

We multiply parentheses

-48x^2-8x

Back to the equation:

-(-48x^2-8x)


We get rid of parentheses

48x^2+8x-16.8=0

a = 48; b = 8; c = -16.8;
Δ = b2-4ac
Δ = 82-4·48·(-16.8)
Δ = 3289.6
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-\sqrt{3289.6}}{2*48}=\frac{-8-\sqrt{3289.6}}{96}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+\sqrt{3289.6}}{2*48}=\frac{-8+\sqrt{3289.6}}{96}
$