Federico needs to frost 36 cupcakes for a party. He has already frosted 23 cupcakes and wants to know how many more he has to frost. He writes the following two equations to represent the problem, but does not know which equation is correct:
23 + c = 36
36 - c = 23
Which equation should Federico use? Explain why
Explain how you know which operation to use when solving an equation, give an example
What don't you understand about my previous answer for this question?
I just need the equation
I mean which equation, my teacher said I could only use one
I told you both are correct.
23 + c = 36
c = 13
36 - c = 23
-c = -13
c = 13
Thank you
You're welcome.
Federico should use the equation 36 - c = 23 to represent the problem correctly.
To determine which equation to use, let's analyze the problem:
Federico has already frosted 23 cupcakes, and he wants to know how many more he has to frost to reach a total of 36 cupcakes. In this context, the phrase "how many more" suggests that we need to subtract a certain quantity (the number of cupcakes already frosted) from another quantity (the total number of cupcakes). Therefore, we should use the subtraction operation.
Using the equation 36 - c = 23, we can solve for the variable c, which represents the number of cupcakes Federico still needs to frost. By subtracting 23 from 36, we find that c = 13. So Federico still needs to frost 13 more cupcakes.
Let's take another example to illustrate how to determine which operation to use when solving an equation:
Suppose Mary has 8 apples, and she wants to know how many more apples she needs to have a total of 15 apples. In this case, we can use the addition operation because Mary needs to add a certain quantity (the number of apples she already has) to another quantity (the number of apples she needs in total).
Using the equation 8 + a = 15, we can solve for the variable a, which represents the number of additional apples Mary needs. By subtracting 8 from 15, we find that a = 7. So Mary needs to get 7 more apples.