2/5x-2/7x=8

Solution for 2/5x-2/7x=8 equation:

2/5x-2/7x=8

We move all terms to the left:

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


Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R



Domain of the equation: 7x!=0

x!=0/7

x!=0

x∈R


We calculate fractions


14x/35x^2+(-10x)/35x^2-8=0

We multiply all the terms by the denominator


14x+(-10x)-8*35x^2=0

Wy multiply elements

-280x^2+14x+(-10x)=0

We get rid of parentheses

-280x^2+14x-10x=0

We add all the numbers together, and all the variables

-280x^2+4x=0

a = -280; b = 4; c = 0;
Δ = b2-4ac
Δ = 42-4·(-280)·0
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-4}{2*-280}=\frac{-8}{-560}
=1/70
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+4}{2*-280}=\frac{0}{-560}
=0
$