7x+5x=(4x-8)x+4x-3x

Solution for 7x+5x=(4x-8)x+4x-3x equation:

7x+5x=(4x-8)x+4x-3x

We move all terms to the left:

7x+5x-((4x-8)x+4x-3x)=0

We add all the numbers together, and all the variables

12x-((4x-8)x+4x-3x)=0


We calculate terms in parentheses: -((4x-8)x+4x-3x), so:

(4x-8)x+4x-3x

We add all the numbers together, and all the variables

x+(4x-8)x

We multiply parentheses

4x^2+x-8x

We add all the numbers together, and all the variables

4x^2-7x

Back to the equation:

-(4x^2-7x)


We get rid of parentheses

-4x^2+12x+7x=0

We add all the numbers together, and all the variables

-4x^2+19x=0

a = -4; b = 19; c = 0;
Δ = b2-4ac
Δ = 192-4·(-4)·0
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19)-19}{2*-4}=\frac{-38}{-8}
=4+3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19)+19}{2*-4}=\frac{0}{-8}
=0
$