-3(-7x+4)-4x=1.5(-5x+8.6)2x

Solution for -3(-7x+4)-4x=1.5(-5x+8.6)2x equation:

-3(-7x+4)-4x=1.5(-5x+8.6)2x

We move all terms to the left:

-3(-7x+4)-4x-(1.5(-5x+8.6)2x)=0

We add all the numbers together, and all the variables

-4x-3(-7x+4)-(1.5(-5x+8.6)2x)=0

We multiply parentheses

-4x+21x-(1.5(-5x+8.6)2x)-12=0


We calculate terms in parentheses: -(1.5(-5x+8.6)2x), so:

1.5(-5x+8.6)2x

We multiply parentheses

-15x^2+25.8x

Back to the equation:

-(-15x^2+25.8x)


We add all the numbers together, and all the variables

-(-15x^2+25.8x)+17x-12=0

We get rid of parentheses

15x^2-25.8x+17x-12=0

We add all the numbers together, and all the variables

15x^2-8.8x-12=0

a = 15; b = -8.8; c = -12;
Δ = b2-4ac
Δ = -8.82-4·15·(-12)
Δ = 797.44
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{-(-8.8)-\sqrt{797.44}}{2*15}=\frac{8.8-\sqrt{797.44}}{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8.8)+\sqrt{797.44}}{2*15}=\frac{8.8+\sqrt{797.44}}{30}
$