SOLUTION: Brian has no more than 16 coins. They comprise of both nickels and dimes. There are at least four times as many nickels as there are dimes. Which of the following is a system of in

That says if you add the number of nickels (x) to the number of
dimes (y) you get a number either less than 16 or equal to 16:

x + y < 16

That says the number of nickels (x) is greater than or equal to 4
times the number of dimes (y).

x > 4y

That's this system:

x + y < 16
x > 4y

Edwin