Answer
a ) Since, $\sqrt{16} \sqrt{4}=8$
b) Since, $\sqrt{(16)(4)}=8$
c) $\sqrt{ab}=\sqrt a \sqrt b$
Work Step by Step
a ) Since, $\sqrt{16} \sqrt{4}=(16)^{1/2} (4)^{1/2}=(4^2)^{1/2} (2^2)^{1/2}= (4)(2)=8$
b) Since, $\sqrt{(16)(4)}=(64)^{1/2}=(8^2)^{1/2}=8$
c) It is true that $\sqrt{ab}=\sqrt a \sqrt b$
