Answer:
bill sold 7525 sandwiches
pete sold 75 sandwiches
Explanation:
we say bills roast beef sells "b" sandwiches and pete sells "p" sandwiches.
set up system of equations
b=7p
b=450+p
7p=450+p
6p=450
p=75
so bill sold 75*7=525 sandwiches
pete sold 75 sandwiches