Plz help. I hope you would at least do 2 screenshots (4 equations), as there can only be 2 answers at a time. Thank you.

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?

X+y=-4 x-y=2 use elimination with adding and subtraction

Aculture started with 4,000 bacteria. after 5 hours, it grew to 5,200 bacteria. predict how many bacteria will be present after 19 hours. round your answer to the nearest whole number.