2/5x+1/4x=39

Solution for 2/5x+1/4x=39 equation:

2/5x+1/4x=39

We move all terms to the left:

2/5x+1/4x-(39)=0


Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R



Domain of the equation: 4x!=0

x!=0/4

x!=0

x∈R


We calculate fractions


8x/20x^2+5x/20x^2-39=0

We multiply all the terms by the denominator


8x+5x-39*20x^2=0

We add all the numbers together, and all the variables

13x-39*20x^2=0

Wy multiply elements

-780x^2+13x=0

a = -780; b = 13; c = 0;
Δ = b2-4ac
Δ = 132-4·(-780)·0
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(13)-13}{2*-780}=\frac{-26}{-1560}
=1/60
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(13)+13}{2*-780}=\frac{0}{-1560}
=0
$