CPM Homework Help : MC1 Problem 1-14

Maria was playing a game with her brother. She said, "I'm thinking of a number. When you multiply my number by six and add seven you get $\textit{25}$ . What is my number?" Find Maria's number.

Hint 1:

How big do you expect her number to be?
Can you think of a reasonable number to try?

Step 1:

Pick a reasonable number and try Maria's steps. Let's try $2$ . If Maria multiplies this number $(2)$ by $6$ , she would get $12$ , then, adding $7$ , she would get $19$ .

Hint 2:

Can you think of a number that might work better? Try it!

Step 2:

Since $19$ is smaller than $25$ , let's choose a bigger number. Let's try $3$ . If Maria multiplies $3$ by $6$ , she would get $18$ . Adding $7$ , she would get $25$ . Since Maria gets $25$ by using this number, $3$ is the number she described.

Answer:

We now know that Maria's number is $3$ .