x+3/10x=-1.31

Solution for x+3/10x=-1.31 equation:

x+3/10x=-1.31

We move all terms to the left:

x+3/10x-(-1.31)=0


Domain of the equation: 10x!=0

x!=0/10

x!=0

x∈R


We add all the numbers together, and all the variables

x+3/10x+1.31=0

We multiply all the terms by the denominator


x*10x+(1.31)*10x+3=0

We multiply parentheses

x*10x+13.1x+3=0

Wy multiply elements

10x^2+13.1x+3=0

a = 10; b = 13.1; c = +3;
Δ = b2-4ac
Δ = 13.12-4·10·3
Δ = 51.61
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(13.1)-\sqrt{51.61}}{2*10}=\frac{-13.1-\sqrt{51.61}}{20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(13.1)+\sqrt{51.61}}{2*10}=\frac{-13.1+\sqrt{51.61}}{20}
$