In this question, you are only able to cancel out the (x + 5). The others are unable to be cancelled.
The answer to your question is 1 and 1/2
1.5 gallons x 3.785 liters x 1000 milliliters
---------------- -------------------- = 5677.5 milliliters
1 gallon 1 liter
#1 is true. The term they have in common is y with an invisible coefficient in-front of the second y term
#2 has zero like terms. 15 has no variable, and the other terms have different variables.
#3 has two like terms, that’s 9 and 8 which add to equal 17. The answer is 3x + 17 aka D.
#4 has two like terms, the numbers with the variable ‘n’. 4n + 7n = 11n. Your answer is 11n + 12 aka D
If I did my math correctly I believe your answer will be C. :)