Three times the sum of a number and seven is equal to ten. Find the number.

Question

This problems goal is to find an unknown number, which I don't know how to go about. 

Answer 1

Let n = the number

 

The sum of a number and 7 is  "n + 7"

Three times the sum of a number and 7 is "3(n + 7)

 

    3(n + 7) = 10

    3n + 21 = 10

    3n = 20 - 21

    3n = -11

    n = -11/3