Let p = [9 15 -4 -7], y_1 (t) = [2e^3t + 6e^-t 3e^3t + 15e^-t], y_2 (t) = [-8e^3t + 2e^-t -12e^3t + 5e^-t]. a. show that y_1 (t) is a solution to the system y' = py by evaluating derivatives and the matrix product y'_1 (t) = [9 15 -4 -7] y_1 (t) enter your answers in terms of the variable t. [] = [] b. show that y_2 (t) is a solution to the system y' = py by evaluating derivatives and the matrix product y'_2 (t) = [9 15 -4 -7] y_2 (t) enter your answers in terms of the variable t. [] = []