9 times a number is that number minus 10 The phrase a number means we define a random/arbitrary variable, let's call it x: x 9 times a number means we multiply x by 9: 9x The phrase that number refers back to the original arbitrary variable we defined above, which is x: x That number minus 10 means we subtract 10 from x: x - 10 The word is means equal to, so we set 9x equal to x - 10 9x = x - 10
