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.
Answer:
The answer is $28.56
Step-by-step explanation:
To find the 2% sales tax, you need to multiply the 2% or 0.02 by 28.
Doing this will give you 0.56.
Then you add 0.56 to 28 to get 28.56, hence, $28.56 is the total cost.
Hope it helps!
Answer:
I don't know if I'm understanding your question correctly. But I'll try...
In this problem you need to remember PEMDAS!
Parentheses, Exponents, Multiplication, Division, Addition, and Subtraction.
18 + 4(28) -First you would multiply 4 by 28 since the 28 is in parentheses.
18 + 112 -Now you would add to find your answer
= 130
I hope this helps!
-Mikayla
Answer:
The answer is "
"
Step-by-step explanation:
Please find the complete question in the attached file.
Calculating the difference of 
dividing the value by 
Answer:
the answer is 26
Step-by-step explanation:
add up all sides
