Kayla and Riley both solved the equation x+15 = 13+7, using substitution. Kayla says the answer is x = 20, and Riley says that answer is x=35. Which student is correct?

Answer 1

To find the correct answer, we need to substitute the potential values of x back into the original equation to check which one is correct.

For Kayla's answer:
x = 20
20 + 15 = 13 + 7
35 = 20
This is not true, so Kayla's answer is incorrect.

For Riley's answer:
x = 35
35 + 15 = 13 + 7
50 = 20
This is also not correct, so Riley's answer is incorrect as well.

Neither student is correct. The correct solution is x = 5.
5 + 15 = 13 + 7
20 = 20
Therefore, the correct answer is x = 5.