-3-3x=-4x(2x+7)

Solution for -3-3x=-4x(2x+7) equation:

-3-3x=-4x(2x+7)

We move all terms to the left:

-3-3x-(-4x(2x+7))=0


We calculate terms in parentheses: -(-4x(2x+7)), so:

-4x(2x+7)

We multiply parentheses

-8x^2-28x

Back to the equation:

-(-8x^2-28x)


We get rid of parentheses

8x^2+28x-3x-3=0

We add all the numbers together, and all the variables

8x^2+25x-3=0

a = 8; b = 25; c = -3;
Δ = b2-4ac
Δ = 252-4·8·(-3)
Δ = 721
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{-(25)-\sqrt{721}}{2*8}=\frac{-25-\sqrt{721}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+\sqrt{721}}{2*8}=\frac{-25+\sqrt{721}}{16}
$