-7x-8=-2(4-1/5x)

Solution for -7x-8=-2(4-1/5x) equation:

-7x-8=-2(4-1/5x)

We move all terms to the left:

-7x-8-(-2(4-1/5x))=0


Domain of the equation: 5x))!=0

x!=0/1

x!=0

x∈R


We add all the numbers together, and all the variables

-7x-(-2(-1/5x+4))-8=0

We multiply all the terms by the denominator


-7x*5x-8*5x-1+4))-(-2(+4))=0

We add all the numbers together, and all the variables

-7x*5x-8*5x-1+4))-(-24)=0

We add all the numbers together, and all the variables

-7x*5x-8*5x=0

Wy multiply elements

-35x^2-40x=0

a = -35; b = -40; c = 0;
Δ = b2-4ac
Δ = -402-4·(-35)·0
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-40}{2*-35}=\frac{0}{-70}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+40}{2*-35}=\frac{80}{-70}
=-1+1/7
$