1 ) f ( 1 ) = 5 * 1 + 1 = 5 + 1 = 6 2 ) f ( x ) = (2 x + 3) / 5 ( we have to find an inverse function ) y = ( 2 x + 3 ) / 5 5 y = 2 x + 3 2 x = 5 y - 3 x = ( 5 y - 3 ) / 2 f^(-1) ( x ) = ( 5 x - 3 ) / 2 f^(-1) ( 3 ) = ( 15 - 3 ) / 2 = 12 / 2 = 6 3 ) 3 y - 7 = y + 5 3 y - y = 5 + 7 2 y = 12 y = 6 Answer: All have the same result.