Question

Simplify : root 45 - 3 root 20 + 4 root 5
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Answer 1

$</p><p> \sf \rightarrow \quad \sqrt{45} - 3 \sqrt{20} + 4 \sqrt{5} \\ \\ \sf \rightarrow \quad \sqrt{5 \times 9} - 3 \sqrt{5 \times 4} + 4 \sqrt{5} \\ \\ \sf \rightarrow \quad 3 \sqrt{5} - 6 \sqrt{5} + 4 \sqrt{5} \\ \\ \sf \rightarrow \quad 7 \sqrt{5} - 6 \sqrt{5} \\ \\ \sf \rightarrow \quad \sqrt{5} </p><p>$

Answer 2

Step-by-step explanation:

√45 - 3√20 + 4√5

√3×3×5 - 3√2×2×5 + 4√5

3√5 - 6√5 + 4√5

=√5

Hence √5 is the simplified value of the given question