The answer is the option C and the option D, which are:
C. Double the number of pages in the book.
D. The age of my friend.
The explanation for this problem is shown below:
By definition, a variable is an unkown quantity. In the Option A the quantity is given: 
seconds in a minute. In the option B you know the quantity too, which is 
years old. But the option C and the option D does not give any quantity, you don't know the number of pages in the book or the age of the friend yet. Therefore, the answer is the options C and D.
The answer you are looking for is 50h+25
Hope that this helps!
Answer:
25
Step-by-step explanation:
I'm sorry but I rlly don't rember how I did it because I did this question on a quiz and the teacher said this was that answer but not how to get it.
Going down the chart:
6
4
3
4
6
the brackets on the outside of the lxl makes the value positive or keeps the value positive. therefor if u have y=l-3l+3 y will still =6! hope this helps!
