Kayla and riley both solved the equation x-15 = 13-7 using substitution Kayla says the answer is x=21 and Riley says that answer is x=28 which student is correct

Question

Kayla

Riley

Neither

Both

Answer 1

To solve the equation x - 15 = 13 - 7 using substitution, we need to substitute x with a value and see if it satisfies the equation.

Let's start with Kayla's answer x = 21:

Substituting x = 21 into the equation:
21 - 15 = 13 - 7
6 = 6

The equation is satisfied.

Now let's test Riley's answer x = 28:

Substituting x = 28 into the equation:
28 - 15 = 13 - 7
13 = 6

The equation is not satisfied.

Therefore, Kayla is correct and the answer is x = 21.