Pls help 15 points! Darren is training for a triathlon. Each week, he goes to the gym for a maximum of 20 hours. He spends at least 8 of those hours weightlifting (x). He wants to spend no more than 15 hours doing cardio exercises (y). Write a system of linear inequalities that represents the restrictions of this scenario.

Saline iv fluid bags cost $64.20 for 24, 1000 ml bags from one supplier. a new supplier sells 500 ml bags for $2 each. the hospital uses about 10,000, 1000 ml bags each month. nurses report that about half of the bags are more than half full when they are discarded. if you are going to use only one supplier, which size bag provides the best deal, and how much will you save each month? compare the cost of the new supplier to the current one.

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Solve each equation using the quadratic formula. find the exact solutions. 6n^2 + 4n - 11