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 to your question would be y2 +5y.
Answer:
20.25
Step-by-step explanation:
45x.40=20.25
5 times 2 plus .015 times 2
Answer:
180 hamburgers
120 hotdogs
Step-by-step explanation:
In this question, we are asked to calculate the number of hamburgers and hotdogs sold by a company given the amount made by them and the total number of these snacks sold
We proceed as follows;
Let the amount of hotdogs sold be x and the amount of hamburgers sold be y.
We have a total of 300 snacks sold, mathematically;
x + y = 300 ..........(I)
Now let’s look at the prices.
x number of hotdogs sold at $2, this give a total of $2x hotdogs
y number of hamburgers sold at $3, this give a total of $3y.
Adding both to give total, we have ;
2x + 3y = 780.......(ii)
This means we have two equations to solve simultaneously. From equation 1, we can say x = 300 -y
Now let’s insert this in the second equation;
2(300-y) + 3y = 780
600-2y + 3y = 780
y = 780-600 = 180
Recall; x + y = 300
x = 300 -y
x = 300-180 = 120
