Question

I’m thinking of a number. If you multiply it by 6 and then add 7 , you will get 55. What is my number

Answer 1

To figure this out, you have to do everything backwards.  Starting with 55, you’re going to subtract 7 leaving you with 48.  Next, you’re going to divide 48 by 6 getting you an answer of 8.  This telling you the answer to this problem is 8.

Answer 2

Let's call the unknown number $n$. Based on the information, we can say:

$6n + 7 = 55$

If we subtract 7 from both sides, we get:

$6n = 48$

When you divide both sides of the equation by 6, we can isolate $n$:

$n = 8$

The number is 8.