Name the set(s) of numbers to which -5 belongs

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 of the following tables represents exponential functions?

Idon’t understand! use slope intercept form to solve: through: (2,5) slope= undefined