Need help for a and b. Here is the question. Thank you!

Let X and Y be random variables withE ( X ) = MX = 40 , SD ( X ) = OX = 10,E ( Y ) = HY = 71, SD ( Y ) = OY = 2, Cor ( X , Y ) = P = – 0. 9 .a . Find E ( 2 X – 7Y ) and SD ( 2 X – 7Y ) . Give your answers to 2 decimal places .E ( 2 X – 7Y ) =SD ( 2 X – 7Y ) =Submit AnswerIncorrect . Tries 1 / 5 Previous Triesb . Let X and Y be random variables withSD ( X ) = OX = 2, SD ( Y ) = OY = 9, SD ( 2 X + 3 Y ) = 28.Find Cor ( X , Y ) = P. Give your answer to 4 decimal places .P =Submit Answer`Tries 0 / 5