Using substitution, which number from the set {6, 13, 18, 26} makes the equation 2x+5=31 true?

We can solve the equation 2x + 5 = 31 using substitution.

Let's try each number from the set {6, 13, 18, 26} and see which one makes the equation true.

1. For x = 6:
2(6) + 5 = 12 + 5 = 17 ≠ 31

2. For x = 13:
2(13) + 5 = 26 + 5 = 31 (True)

3. For x = 18:
2(18) + 5 = 36 + 5 = 41 ≠ 31

4. For x = 26:
2(26) + 5 = 52 + 5 = 57 ≠ 31

Therefore, the number that makes the equation 2x + 5 = 31 true is x = 13.