PLEASE HELP!

It's Thanksgiving and your Uncle Buck gives you a bucket of coins as a gift. In the bucket you see quarters, nickels, and golden dollars. He tells you there is $157 in the bucket and you count a total of 740 coins. If there are twice as many nickels as quarters, how many of each type are in the bucket?
Let Q = number of quarters, N = number of nickels, and D = number of golden dollars.
1. Set up 3 equations with the 3 given variables above.
(Hint: If you want to take 5 cents, it’s .05 dollars. Many people put .5 by accident.)
2. Put the system of equations into triangular form.
3. Solve the system and check your answer.