Avery old vending machine accepts only nickels (n) and dimes (d). candy costs up to $0.50, but sometimes the machine will dispense candy without any coins being inserted into the machine. which inequality shows all of the ways to obtain a candy bar from the machine

Candy costs up to $0.50. that means it can cost only till 0.50 no higher than that and 0.50 itself so. 50 cents is 1/2 a dollar.

Now a nickel equals 5 cents. 5 cents is 1/20th of a dollar.
Remember, one dollar = 100 cents

A dime equals 10 cents. 10 cents is 1/10th of a dollar

We get the inequality https://us-static.z-dn.net/files/dde/db6daa3dfec0dea125aa0f6b45bd6fdc.png as your final answer.