Question

Foster’s answer to the question he wrote for Ranger was 7x + (–3), while Ranger’s answer was 7x – 3. They both checked their work by letting x = 5, and they both claim to be correct. Are they both correct? Explain.

Answer 1

Yes.

Explanation:

7(5) + (-3) = 32

7(5) + -3 = 32

Both of the equations have the same answer so it's correct.

Answer 2

Both Foster and Ranger are correct because subtracting 3 is the same as adding –3. If you let x = 5 in either of the expressions, you get the answer 32.