1.3*10^-3=x^2/1.25-x

Solution for 1.3*10^-3=x^2/1.25-x equation:

1.3*10^-3=x^2/1.25-x

We move all terms to the left:

1.3*10^-3-(x^2/1.25-x)=0


Domain of the equation: 1.25-x)!=0

We move all terms containing x to the left, all other terms to the right

-x)!=-1.25

x!=-1.25/1

x!=-1.25

x∈R


We add all the numbers together, and all the variables

-(x^2/1.25-x)=0

We get rid of parentheses

-x^2/1.25+x=0

We multiply all the terms by the denominator


-x^2+x*1.25=0

We add all the numbers together, and all the variables

-1x^2+x*1.25=0

Wy multiply elements

-1x^2+1.25x=0

a = -1; b = 1.25; c = 0;
Δ = b2-4ac
Δ = 1.252-4·(-1)·0
Δ = 1.5625
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{-(1.25)-\sqrt{1.5625}}{2*-1}=\frac{-1.25-\sqrt{1.5625}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.25)+\sqrt{1.5625}}{2*-1}=\frac{-1.25+\sqrt{1.5625}}{-2}
$