test the exactness of differential equation

1. show that y = ex cost is a solution of y" - 24 + 2 4= 0 2. show that y= 2 + ex is a solution of y' + 2 x y = 4x TEST EXACTNESS AND solve THE EQUATION 1. ( 2 x y + y ) d x + ( x 2 - x ) dy = 0 2 . ( 2 x - 3 4 ) d x + ( 2 4 - 3x ) dy = 0