Answer:
x=1/7
Step-by-step explanation:
List the multiples of each qty:
7, 14, 21, 28,35,42,49,56,63
9, 18, 27, 36, 45, 54, 63
The least common multiple is 63
He bought 63 hotdogs and buns
It crosses the y-axis at (0,5)
It crosses the x-axis at (20,0)