Jon and lexi are playing a marble game. according to their rules, 4 points are awarded for each red marble collected and 7 points are awarded for each blue marble collected. which expression represents jon's total score if he has r red marbles and b blue marbles?

Let the variable r represent the amount of red marbles that Jon has, and the variable b represent the amount of blue marbles that Jon has.

Because 4 points are awarded for each red marble collected, 4 will be the coefficient of the variable r (red marbles).

Because 7 points are awarded for each blue marble collected, 7 will be the coefficient of the variable b (blue marbles).

Therefore, the expression of Jon's total score is 

4r + 7b

Hope this helps! :)