Answer:
24 = 77 - c
Step-by-step explanation:
Since both started off with an initial amount of money and then made a purchase to end up with the same amount of money this can be represented as the following where x is the amount of money left over and c is the cost of the chemistry set.
60 - 36 = x
77 - c = x
Since both are equal to x we can simply make both equations equal to one another.
60 - 36 = 77 - c ... simplify it by subtracting 60 - 36
24 = 77 - c
We can now solve this equation
24 = 77 - c ... subtract 77 from both sides
-53 = -c ... the negatives cancel out
53 = c
