Question

u
$\sqrt{45 } - 3 \sqrt{20} + 4 \sqrt{5}$
nderoot 45 -3 underoot 20 +4 underoot 5​

Answer 1

$\small\red{\boxed{question = \sqrt{45 } - 3 \sqrt{20} + 4 \sqrt{5}}} \\ \\ \: solution : - \\ \\ \sqrt{45} - 3 \sqrt{20} + 4 \sqrt{5} \\ = \sqrt{3 \times 3 \times 5} - 3 \sqrt{2 \times 2 \times 5 } + 4 \sqrt{5} \\ = 3 \sqrt{5} - 3 \times 2 \sqrt{5} + 4 \sqrt{5} \\ = 3 \sqrt{5} - 6 \sqrt{5} + 4 \sqrt{5} \\ = 7 \sqrt{5} - 6 \sqrt{5} \\ \tt \green{ \sqrt{5} \: \: answer...}$