Explanation: if there were thirteen friends to begin with and six quit that would leave them with 7 friends. If those seven remaining friends each had 8 lives, you multiply those 7 friends by 8 lives which would get 56.
If all thirteen friends were still in the game then they would have 104 lives all together.
3x + 24 = (3)(x) + (3)(8) You can see that there is multiplier 3 near x and 8. You can factor it and make 3x + 24 = 3(x + 8) So, the answer is 3. Hope this helps!