### Home > CC2MN > Chapter cc21 > Lesson cc21.1.3 > Problem1-18

1-18.

Thu wants to play “Guess My Number.” She states, “When I triple my number and add five, I get twenty-six. What is my number?” What is her number? Show how you know. Homework Help ✎

To triple means to multiply by $3$, so:

$3x+5=26$

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.