X+9=1/7y

Solution for X+9=1/7y equation:

X+9=1/7X

We move all terms to the left:

X+9-(1/7X)=0


Domain of the equation: 7X)!=0

X!=0/1

X!=0

X∈R


We add all the numbers together, and all the variables

X-(+1/7X)+9=0

We get rid of parentheses

X-1/7X+9=0

We multiply all the terms by the denominator


X*7X+9*7X-1=0

Wy multiply elements

7X^2+63X-1=0

a = 7; b = 63; c = -1;
Δ = b2-4ac
Δ = 632-4·7·(-1)
Δ = 3997
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{-(63)-\sqrt{3997}}{2*7}=\frac{-63-\sqrt{3997}}{14}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(63)+\sqrt{3997}}{2*7}=\frac{-63+\sqrt{3997}}{14}
$