Question

which irrational is larger 4√20 or3√15

Answer 1

4√20 is 17.88 and 3√15 is 11.61......so 4√20 is larger.

Answer 2

$4 \sqrt{20 } = 4 \times 2 \sqrt{5} = 8 \sqrt{5} = 17.8885... \\ 3 \sqrt{15 } = 11.61...$
Therefore, 4root20 is bigger than 3root15