-5x + y = 35 and 3x + 2y = -21 How would I solve by substitution?

The green family is a family of six people. they have used 4,885.78 gallons of water so far this month. they cannot exceed 9,750.05 gallons per month during drought season. write an inequality to show how much water just one member of the family can use for the remainder of the month, assuming each family member uses the same amount of water every month.

Find the greatest common factor of the followig monomials 21u^5v,3u^4v^6, and 3u^2v^5

21 a stick 7 inches long is broken into two pieces, so that one piece is twice as long as the other one. how long are the two pieces?