Solve the following quadratic using any method: $x^ 2 = 64 .$
A) $x = 8$
B) $x = 8 i$
C) $x = 8 , - 8$
D) $x = 8 i , - 8 i$

Question

Quizplus · Accepted Answer

To solve this quadratic, we can take the square root of both sides:

$$x^2 = 64$$ 
$$\Rightarrow \sqrt{x^2} = \sqrt{64}$$ 
$$\Rightarrow |x| = 8$$

Note that we need to include the absolute value bars since we are taking the square root of a squared variable. Thus, the solutions for $x$ are $x = 8$ and $x = -8$. Option C includes both of these solutions, therefore it is the best choice. Option A is incorrect because it only includes one of the solutions. Options B and D are incorrect because they include imaginary solutions, which are not applicable in this case since we are dealing with a real quadratic.

Solve the Following Quadratic Using Any Method x2=64.x^ 2 = 64 .x2=64.

Solve the Following Quadratic Using Any Method $x^ 2 = 64 .$