Answer:
11
Explanation:
Work backwards and reverse the operations to find the original number.
Reverse the operations for add four: 8 - 4 = 4
Reverse the operations for take the square root: 4² = 16
Reverse the operations for subtract six: 16 + 6 = 22
Reverse the operations for double the number: 22 ÷ 2 = 11