1/5x+x=42

Solution for 1/5x+x=42 equation:

1/5x+x=42

We move all terms to the left:

1/5x+x-(42)=0


Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R


We add all the numbers together, and all the variables

x+1/5x-42=0

We multiply all the terms by the denominator


x*5x-42*5x+1=0

Wy multiply elements

5x^2-210x+1=0

a = 5; b = -210; c = +1;
Δ = b2-4ac
Δ = -2102-4·5·1
Δ = 44080
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{44080}=\sqrt{16*2755}=\sqrt{16}*\sqrt{2755}=4\sqrt{2755}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-210)-4\sqrt{2755}}{2*5}=\frac{210-4\sqrt{2755}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-210)+4\sqrt{2755}}{2*5}=\frac{210+4\sqrt{2755}}{10}
$