Help? I’m having trouble understanding…

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.

The areas of two similar triangles are 72dm2 and 50dm2. the sum of their perimeters is 226dm. what is the perimeter of each of these triangles?

Use sigma notation to represent the following series for 9 terms.