Question

simplify the radical expression.

1. $sqrt{20} + sqrt{45} - sqrt{5}$

Explanation:

Step1: Simplify each radical

$\sqrt{20} = \sqrt{4 \times 5} = 2\sqrt{5}$, $\sqrt{45} = \sqrt{9 \times 5} = 3\sqrt{5}$, $\sqrt{5}$ remains as is

Step2: Substitute simplified radicals

$2\sqrt{5} + 3\sqrt{5} - \sqrt{5}$

Step3: Combine like radicals

$(2 + 3 - 1)\sqrt{5} = 4\sqrt{5}$

Answer:

$4\sqrt{5}$