x^2+1=7x^2/9+3

Solution for x^2+1=7x^2/9+3 equation:

x^2+1=7x^2/9+3

We move all terms to the left:

x^2+1-(7x^2/9+3)=0

We get rid of parentheses

x^2-7x^2/9-3+1=0

We multiply all the terms by the denominator


-7x^2+x^2*9-3*9+1*9=0

We add all the numbers together, and all the variables

-7x^2+x^2*9-18=0

Wy multiply elements

-7x^2+9x^2-18=0

We add all the numbers together, and all the variables

2x^2-18=0

a = 2; b = 0; c = -18;
Δ = b2-4ac
Δ = 02-4·2·(-18)
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12}{2*2}=\frac{-12}{4}
=-3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12}{2*2}=\frac{12}{4}
=3
$