Answer:
16r - 250 = 768
Step-by-step explanation:
First, create a term that represents his revenue:
Since he charges students $16 per hour, the amount of money he makes from this can be represented by 16r.
Then, subtract the advertising cost of $250 from this.
Set it equal to 768, because that is how much the gaming system costs.
16r - 250 = 768 will be the equation