Respuesta :

Hey there!

4x² = 81

x² = 81 ÷ 4

x² = 20.25

x = √20.25

x = 4.5

Hope it helps ya!

[tex] \huge \boxed{\mathbb{QUESTION} \downarrow}[/tex]

  • Solve for x ⇨ 4x² = 81.

[tex] \large \boxed{\mathfrak{Answer \: with \: Explanation} \downarrow}[/tex]

[tex] \sf \: 4 x ^ { 2 } = 81[/tex]

Divide both sides by 4.

[tex] \sf \: x^{2}=\frac{81}{4} \\ [/tex]

Take the square root of both sides of the equation.

[tex] \sf \: x \: = \sqrt{ \frac{81}{4} } \\ [/tex]

Now, simplify it.

[tex] \boxed{ \boxed{ \bf \: x = + \frac{9}{2} \: or \: - \frac{9}{2} }} \\ [/tex]

This can be further simplified to ..

[tex] \boxed{ \boxed{ \bf \: x \: = + \: 4.5 \: or \: - 4.5}}[/tex]

NOTE :-

  • You can solve this equation using the quadratic formula or by finding the difference of the squares. I've found the answer by using the easiest method ⇨ finding the square root method.