If a line segment has endpoints a(3x+5, 3y) and b(x-1,-y), what are the coordinates of the midpoint of ab

Given that de, df, and ef are midsegments of △abc, and de=3.2 feet, ef=4 feet, and df=2.4 feet, the perimeter of △abc is .

Which is the graph of the function y=2(4)^x

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years