Let x= months
So 50x is the total amount he pays after x months. You went to add 100 to this because there's a fixed cost of 100 for the phone
So you have the expression 100+50x which is the amount he pays after x months
Since he has a limit of 300,
100+50x < 300
So firstly, we have to find the LCD, or lowest common denominator, of 9 and 7. To do this, list the multiples of 9 and 7 and the lowest multiple they share is going to be your LCD. In this case, the LCD of 9 and 7 is 63. Multiply x^2/9 by 7/7 and 2y/7 by 9/9:

Next, add the numerators together, and your answer will be: 
Answer:
The last one, Explanatory variable: player 40-yard-dash time
Response variable: player weight would be your answer. Hope this helps : )
Step-by-step explanation: