Question

evaluate

Answer 1

\[3\sqrt{-64}\]

Answer 2

\[\large \sqrt{-64} \implies \sqrt{(-1) \times 64} \implies \sqrt{(-1)} \times \sqrt{64} \implies i8\]

Answer 3

So:

\[\large 3 \times i \times 8 = ??\]

Answer 4

whats i?

Answer 5

You can split -64 into factors like this:
\[\sqrt[3]{-64}=\sqrt[3]{-1 \times 64}=\sqrt[3]{-1} \times \sqrt[3]{64}\]
Then you find the cube root of 64, either by knowing it already or by taking factors.
\[\sqrt[3]{64}=\sqrt[3]{2 \times 2 \times 2 \times 2 \times 2 \times 2}=2^2=4\]
Since the cube root of -1 is -1, the final answer is -1 x 4 = -4.