X=2y/7y-9

Solution for X=2y/7y-9 equation:

X=2X/7X-9

We move all terms to the left:

X-(2X/7X-9)=0


Domain of the equation: 7X-9)!=0

X∈R


We get rid of parentheses

X-2X/7X+9=0

We multiply all the terms by the denominator


X*7X-2X+9*7X=0

We add all the numbers together, and all the variables

-2X+X*7X+9*7X=0

Wy multiply elements

7X^2-2X+63X=0

We add all the numbers together, and all the variables

7X^2+61X=0

a = 7; b = 61; c = 0;
Δ = b2-4ac
Δ = 612-4·7·0
Δ = 3721
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3721}=61$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(61)-61}{2*7}=\frac{-122}{14}
=-8+5/7
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(61)+61}{2*7}=\frac{0}{14}
=0
$