### Home > MC2 > Chapter 1 > Lesson 1.1.3 > Problem 1-17

1-17.

To triple means to multiply by 3, so:

3 · ? + 5 = 26

Thu's number cannot be 10 because...

3 · 10 + 5 = 35

So what can her number be?

Her number is 7. Be sure to show why this is the answer.