a rectangle has an area of x^2+10x+21 square units. name the expression that describes the shorter side of the rectangle

There are 20 children in the cast of a class play and 8 of the children are boys of the boys 4 have a speaking part in the play and of the girls 8 do not have a speaking part in the play if a child from the cast of the place chosen at random what is the probability that the child has a speaking part

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?