Question

multiply (-8 radical 21) (-7 radical 2). give an exact answer please
A. 56 radical 19
B. -56 radical 42
C. - radical 42
D. 56 radical 42

Answer 1

To multiply \((-8 \sqrt{21})\) and \((-7 \sqrt{2})\), we can follow these steps:

1. Multiply the coefficients: \(-8 \times -7 = 56\).
2. Multiply the radicals: \(\sqrt{21} \times \sqrt{2} = \sqrt{42}\).

Putting it all together, we have:

\[
(-8 \sqrt{21}) \times (-7 \sqrt{2}) = 56 \sqrt{42}
\]

Therefore, the exact answer is:

D. \(56 \sqrt{42}\)