I think this is a function..
Answer:
(^6√x^5) (√y)
(The 6 belongs in the left on top of the square root btw)
For x the 6 moves to the front of the square root while the 5 becomes the power of x.
For y, the power to the 1/2 is the same as a square root.
The digit 7 is in the tens place so 74 will become either 70 or 80 after rounding off to the nearest ten. Draw a number line with 3 numbers on it: 70, 75 and 80. (Both possible rounded off numbers and the number in the middle.
Answer:400. 10^2 x 12/3 = 400.