Solve the equation. $x ^ { 2 } = 9$
A) $x = 0$
B) $x = 19$
C) $x = \pm 9$
D) $x = \pm 3$
E) none of these

Name: Solve the equation. $x ^ { 2 } = 9$ A) $x = 0$ B) $x = 19$ C) $x = \pm 9$ D) $x = \pm 3$ E) none of these
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Quizplus · Accepted Answer

Squaring a number always yields a non-negative result, so we don't need to consider negative values for $x$. 
We can quickly see that $x=3$ and $x=-3$ are both solutions because $3^2 = 9$ and $(-3)^2 = 9$. 
Therefore, the answer is $x = \pm 3$, which is choice D.

Solve the Equation x2=9x ^ { 2 } = 9x2=9 A) x=0x = 0x=0

Solve the Equation $x ^ { 2 } = 9$ A) $x = 0$