Question

Mike and his friends bought cheese wafers for $2 per packet and chocolate wafers for $1 per packet at a carnival. They spent a total of $25 to buy a total of 20 packets of wafers of the two varieties.
Part A: Write a system of equations that can be solved to find the number of packets of cheese wafers and the number of packets of chocolate wafers that Mike and his friends bought at the carnival. Define the variables used in the equations.

Part B: How many packets of chocolate wafers and cheese wafers did they buy? Explain how you got the answer and why you selected a particular method to get the answer.

Answer 1

Answer:

A) x will represent cheese wafers and y will be the chocolate ones.x+y=20 and 2x+y=25 are the system of equations.  

B) Let's line them up because that makes it easier. I'm using the elimination method so I'm gonna reverse the signs.

                                               - x+-y=-20

                                             2x+y=25    

so subtract 2x from -1x and subtract y from -y and 20 from 25 so you equation so now we are left with x = 5 so we know they bought 5 cheese wafers. Now we need to know y so substitute 5 for x into x + y= 20 so 5 + y = 20 now simplify so y=15 now we know they bought 15 chocolate wafers.  

I choose the elimination method because it is one of the easiest methods and it is fun to cancel out numbers.

Step-by-step explanation:

Answer 2

A)  x = number of cheese wafers          y = number of chocolate wafers
      2x + y = 25
      x + y = 20

B)  2x + y = 25
      -x + -y = -20       Reverse the signs for elimination
       x = 5                  They purchased 5 cheese wafers

       x + y = 20         Substitute the known variable
       5 + y = 20         Simplify
       y = 15               They purchased 15 chocolate wafers