Question

simplify:
$6\sqrt{3} \cdot 3\sqrt{21}$

Explanation:

Step1: Multiply coefficients

$6 \times 3 = 18$

Step2: Multiply radical terms

$\sqrt{3} \times \sqrt{21} = \sqrt{3 \times 21}$

Step3: Simplify the product inside radical

$\sqrt{63} = \sqrt{9 \times 7} = \sqrt{9} \times \sqrt{7} = 3\sqrt{7}$

Step4: Multiply result with coefficient

$18 \times 3\sqrt{7} = 54\sqrt{7}$

Answer:

$54\sqrt{7}$