Priscilla has a number riddle for her friends. She wants them to guess what number she is thinking of. She tells them that her number can be represented by the x in the equation 3x−10=26. Her friends guess {6, 12, 13, 36}. Using substitution, which guess was the correct number?

Answer 1

To find out which guess was the correct number, we can substitute each guess into the equation and see which one satisfies the equation.

Let's start with 6:

3x - 10 = 26

3(6) - 10 = 18 - 10 = 8

6 does not satisfy the equation.

Now let's try 12:

3x - 10 = 26

3(12) - 10 = 36 - 10 = 26

12 satisfies the equation!

We don't need to check the other guesses because we already found the correct one. Therefore, the answer is 12.