Answer: x = 9/2, Option B
We are given the equation
4x^2 = 81
Firstly, we will need to divide both sides by 4
4x^2 / 4 = 81/4
x^2 = 81/4
Take the squareroots of both sides
[tex]\begin{gathered} \sqrt[]{x^2}\text{ = }\sqrt[]{\frac{81}{4}} \\ x=\text{ }\pm\text{ }\frac{9}{2} \end{gathered}[/tex]