Question

explain how to solve this pls pls pls pls

Answer 1

hey mate...
here is your answer...

put the value of
$\sqrt{5}$
and then multiple into 4...

hope it will be helpful for you

Answer 2

$\sqrt{80 } = \sqrt{16 \times 5} \: but \sqrt{16} = 4 \: therefore4 \sqrt{5}$