I need help and guidance with there 3 problems 1) The sum of three numbers is 17. The sum of twice the first number, 4 times the second number, and 5 times the third number is 66. The difference between 7 times the first number and the second number is 31. Find the three numbers. 2) On a recent trip to the convenience store, you picked up 2 gallons of milk, 6 bottles of water, and 5 snack-size bags of chips. Your total bill (before tax) was $24.20. If a bottle of water costs twice as much as a bag of chips, and a gallon of milk costs $1.60 more than a bottle of water, how much does each item cost? 3) Use a system of linear equations in three variables to solve the following problem. At a college production of a play, 400 tickets were sold. The ticket prices were $8, $10, and $12, and the total income from ticket sales was $3660. How many tickets of each type were sold if the combined number of $8 and $10 tickets sold was 7 times the number of $12 tickets sold