4/5x-1/3x=15

Solution for 4/5x-1/3x=15 equation:

4/5x-1/3x=15

We move all terms to the left:

4/5x-1/3x-(15)=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


12x/15x^2+(-5x)/15x^2-15=0

We multiply all the terms by the denominator


12x+(-5x)-15*15x^2=0

Wy multiply elements

-225x^2+12x+(-5x)=0

We get rid of parentheses

-225x^2+12x-5x=0

We add all the numbers together, and all the variables

-225x^2+7x=0

a = -225; b = 7; c = 0;
Δ = b2-4ac
Δ = 72-4·(-225)·0
Δ = 49
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{49}=7$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(7)-7}{2*-225}=\frac{-14}{-450}
=7/225
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+7}{2*-225}=\frac{0}{-450}
=0
$