1/4x-3/8x=20

Solution for 1/4x-3/8x=20 equation:

1/4x-3/8x=20

We move all terms to the left:

1/4x-3/8x-(20)=0


Domain of the equation: 4x!=0

x!=0/4

x!=0

x∈R



Domain of the equation: 8x!=0

x!=0/8

x!=0

x∈R


We calculate fractions


8x/32x^2+(-12x)/32x^2-20=0

We multiply all the terms by the denominator


8x+(-12x)-20*32x^2=0

Wy multiply elements

-640x^2+8x+(-12x)=0

We get rid of parentheses

-640x^2+8x-12x=0

We add all the numbers together, and all the variables

-640x^2-4x=0

a = -640; b = -4; c = 0;
Δ = b2-4ac
Δ = -42-4·(-640)·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*-640}=\frac{0}{-1280}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+4}{2*-640}=\frac{8}{-1280}
=-1/160
$