Question

I need help with algebra 2 pleasee

Answer 1

Answer:

$x=\pm \sqrt{21}/7$

Step-by-step explanation:

We can add 9 to both sides of the equation to get $21x^2=9$.

We can divide both sides of the equation by 21 to get $x^2=9/21$.

We take the square root of both sides of the equation to get $x=\pm \sqrt{9/21}$.

However, that isn't in the form we need.

We know that $\sqrt{9/21}=\sqrt{9}/\sqrt{21}=3/\sqrt{21}=3\sqrt{21}/(\sqrt{21}*\sqrt{21})=3\sqrt{21}/21=\sqrt{21}/7$

so the answer is really $x=\pm \sqrt{21}/7$ and we're done!