Based on the given problem above, this number, when he multiplies this number by 6, and subtracts from 15 from the answer, he ends up with his original number. So let us put x as the original number. So it would end like this.
6x - 15 = x
6x - x = 15
5x = 15 (divide both sides by 5) and the answer is
x = 3
Therefore, the original number that Ryan is thinking is number 3.
Hope this answers your question.
