PLEASE HELP! SOLVE THIS SYSTEM BY ELIMINATION. SHOW ALL OF YOUR WORK.

5X-4Y=3
-10X+7Y= -4​

Aswimming pool has an input pump for filling the pool and an output pump for emptying the pool. the input pump can fill the pool in 3 hours, and the output pump can drain the pool in 5 hours. as you go to bed, the pool is full, but a neighbor’s kid turns on the output pump. at midnight, you awake to find the pool half empty. immediately, you turn on the input pump, but you are sleepy and forget to turn off the output pump. at what time will the pool become full?

An elevator travels 310 feet in 10 seconds. at that speed, how far can't his elevator travel in 12 seconds?

Mike wants to make meatloaf. his recipe uses a total of 8 pounds of meat. if he uses a 3 to 1 ratio of beef to pork, how much pork will he use? enter your answer as a mixed number in simplest terms.