Could someone please check my work?

1. 11 ) verify that Var ( x ) = E [ X ] ] - ( E [ x] ) 2 Var ( X ) = = [ ( x - = [ x ] ) = ] = = [(x- MX ) =]' = E[ X 2 - 2 x X + MX ] = E [ x 3 ] - 2 My E [ x] + = [M; ] = =[ x 3 ] - 2 MX + MX = =[x 2 ] - MX 2 = E[ x 2 ] - (=[x])