If 5 is subtracted from a number, and the difference is tripled, the result is 7 less than the number.

Question

If 5 is subtracted from a number, and the difference is tripled, the result is 7 less than the number. Find the number and explain solution. Don’t use decimal notations.

Answer 1

3(x-5)=x-7

3x - 15 = x - 7

Subtract x from each side and then add 15 to each side:

2x = 8

x=4

 

Plug 4 back into the original problem to make sure the answer is correct.