-1/5x-12=-0.2x-12

Solution for -1/5x-12=-0.2x-12 equation:

-1/5x-12=-0.2x-12

We move all terms to the left:

-1/5x-12-(-0.2x-12)=0


Domain of the equation: 5x!=0

x!=0/5

x!=0

x∈R


We get rid of parentheses

-1/5x+0.2x+12-12=0

We multiply all the terms by the denominator


(0.2x)*5x+12*5x-12*5x-1=0

We add all the numbers together, and all the variables

(+0.2x)*5x+12*5x-12*5x-1=0

We multiply parentheses

0x^2+12*5x-12*5x-1=0

Wy multiply elements

0x^2+60x-60x-1=0

We add all the numbers together, and all the variables

x^2-1=0

a = 1; b = 0; c = -1;
Δ = b2-4ac
Δ = 02-4·1·(-1)
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2}{2*1}=\frac{-2}{2}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2}{2*1}=\frac{2}{2}
=1
$