Question

simplify $3\sqrt{20} - 2\sqrt{5} + 2\sqrt{45}$
solution
$10\sqrt{5}$
decimal
$22.36067...$

Explanation:

Step1: Simplify each radical term

$3\sqrt{20}=3\sqrt{4\times5}=3\times2\sqrt{5}=6\sqrt{5}$
$2\sqrt{45}=2\sqrt{9\times5}=2\times3\sqrt{5}=6\sqrt{5}$

Step2: Substitute simplified terms

$6\sqrt{5}-2\sqrt{5}+6\sqrt{5}$

Step3: Combine like radical terms

$(6-2+6)\sqrt{5}=10\sqrt{5}$

Answer:

$10\sqrt{5}$ (or decimal approximation $22.36067...$)