<span> (3 + 1/4 u^4 − 2/3 u^9) du</span>
This is true for any decimals below 1:
If you multiply a number by something greater than 1, it increases
If you multiply a number by 1, it stays the same
If you multiply a number by something less than 1, it decreases
C is your answer because you count 1 square a block