when you take a normal square root, that's also the same is raising to the 1/2 power. So you need the 5th root of 15, or 15^(1/5) = 1.71877...
BUT, multiplication comes first, order of operations
so 2.24 * 2 = 4.48
Add 15^(1/5) to 4.48 and keep as many decimals as you need
