3/4x+1/5x+4=0

Solution for 3/4x+1/5x+4=0 equation:

3/4x+1/5x+4=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


15x/20x^2+4x/20x^2+4=0

We multiply all the terms by the denominator


15x+4x+4*20x^2=0

We add all the numbers together, and all the variables

19x+4*20x^2=0

Wy multiply elements

80x^2+19x=0

a = 80; b = 19; c = 0;
Δ = b2-4ac
Δ = 192-4·80·0
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19)-19}{2*80}=\frac{-38}{160}
=-19/80
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19)+19}{2*80}=\frac{0}{160}
=0
$