1/4x+2/5x=3

Solution for 1/4x+2/5x=3 equation:

1/4x+2/5x=3

We move all terms to the left:

1/4x+2/5x-(3)=0


Domain of the equation: 4x!=0

x!=0/4

x!=0

x∈R



Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R


We calculate fractions


5x/20x^2+8x/20x^2-3=0

We multiply all the terms by the denominator


5x+8x-3*20x^2=0

We add all the numbers together, and all the variables

13x-3*20x^2=0

Wy multiply elements

-60x^2+13x=0

a = -60; b = 13; c = 0;
Δ = b2-4ac
Δ = 132-4·(-60)·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*-60}=\frac{-26}{-120}
=13/60
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(13)+13}{2*-60}=\frac{0}{-120}
=0
$