Multiply and simplify the expression $\sqrt { 5 } \sqrt { 21 }$ .
A) 105
B) $\sqrt { 105 }$
C) $\sqrt { 5 } + \sqrt { 21 }$
D) $\sqrt { 21 }$
E) $\sqrt { 5 }$

Question

Quizplus · Accepted Answer

When multiplying square roots, we can simply multiply the numbers inside the roots. Thus, $\sqrt{5} \cdot \sqrt{21} = \sqrt{5 \cdot 21} = \sqrt{105}$. Choice B matches this simplified answer.

Multiply and Simplify the Expression 521\sqrt { 5 } \sqrt { 21 }5​21​

Multiply and Simplify the Expression $\sqrt { 5 } \sqrt { 21 }$