1/4x+3/8x=15

Solution for 1/4x+3/8x=15 equation:

1/4x+3/8x=15

We move all terms to the left:

1/4x+3/8x-(15)=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^2-15=0

We multiply all the terms by the denominator


8x+12x-15*32x^2=0

We add all the numbers together, and all the variables

20x-15*32x^2=0

Wy multiply elements

-480x^2+20x=0

a = -480; b = 20; c = 0;
Δ = b2-4ac
Δ = 202-4·(-480)·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-20}{2*-480}=\frac{-40}{-960}
=1/24
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+20}{2*-480}=\frac{0}{-960}
=0
$