Please help in simplify these expressions

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 .

Drag the tiles to the correct boxes to complete the pairs. using the properties of integer exponents, match each expression with the correct equivalent expression.

Graph the system of equations on your graph paper to answer the question. {y=−x+4y=x−2 what is the solution for the system of equations? enter your answer in the boxes.