1/5x+1/3x=8

Solution for 1/5x+1/3x=8 equation:

1/5x+1/3x=8

We move all terms to the left:

1/5x+1/3x-(8)=0


Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R



Domain of the equation: 3x!=0

x!=0/3

x!=0

x∈R


We calculate fractions


3x/15x^2+5x/15x^2-8=0

We multiply all the terms by the denominator


3x+5x-8*15x^2=0

We add all the numbers together, and all the variables

8x-8*15x^2=0

Wy multiply elements

-120x^2+8x=0

a = -120; b = 8; c = 0;
Δ = b2-4ac
Δ = 82-4·(-120)·0
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-8}{2*-120}=\frac{-16}{-240}
=1/15
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+8}{2*-120}=\frac{0}{-240}
=0
$