lets reverse engineer this. 4x=40. What is known in this? We know 40 is the unit amount of 4x. So we need to find out what x is, than multiply it by 4. We can do this by doing the opposite of multiplying, which is dividing! So we divide 4 by 40, which we get the answer 10! We know this is the correct answer because we can factor it into the equation. So 4*10=40!!! hope this helped!!!
