Aalisha J. answered 05/26/18
Tutor
New to Wyzant
Musician and Mathematician
If you count d as the number of hot dogs per minute, 9d would be how many hot dogs he eats in 9 minutes, which is what's left.
9d + 10 is the expression that shows how many hot dogs he will eat in total: 9d being how much he'll eat in the remaining 9 minutes, and 10 being the number of hot dogs he's already eaten in the first minute.
Since it has to beat his former record of 72, it has to be greater than 72. The inequality would be
9d + 10 > 72
Then you can solve for d to find how many he has to eat in the remaining 9 minutes.
9d > 72 - 10
9d > 62
d > 62/9
It asks for the minimum WHOLE number of hot dogs he has to eat to break his record. 62/9 is about 6.89, so since d > 6.89, he needs to eat at least 7 hot dogs PER MINUTE in the remaining 9 minutes to beat his old score!