Write $- 3 \sqrt { - 147 }$ in terms of i and simplify.
A) $21 i \sqrt { 3 }$
B) $- 21 \sqrt { 3 }$
C) $- 21 i \sqrt { 3 }$

Question

Quizplus · Accepted Answer

We know that $\sqrt{-1}$ is equal to $i$. We also know that $\sqrt{147}$ is equal to $\sqrt{49 \cdot 3}$, which simplifies to $7\sqrt{3}$. Putting these two pieces together, we get: $$-3\sqrt{-147} = -3\sqrt{-1 \cdot 147} = -3\sqrt{-1} \cdot \sqrt{147} = -3i \cdot 7\sqrt{3} = -21i\sqrt{3}$$ Therefore, the best choice is C.

Write −3−147- 3 \sqrt { - 147 }−3−147​ In Terms of I and Simplify

Write $- 3 \sqrt { - 147 }$ In Terms of I and Simplify