My guess is 30 mins sorry if wrong hope this helps

$=\sqrt{4^2}\times\sqrt{2^2\cdot3}$
$=4\times2\sqrt3=8\sqrt3$
2×4=8 because 2 and 4 would be the addends and their less than 5 and it equal an answer between 4 and 10
It states your "X" will be zero when solving for "Y".
So when solving for "Y" your equation would be;
0+y=4
Then you solve. Y=4
Then you do the same with the "X":
X+0=4. Then you solve. X=4
It would end up being (4(x),4(y) )
Then do the same for the next problem.