23. Find for the equation 3x - 5y = 50 at the point (1, - 2). [4 marks] 24. Determine the slope of the tangent of f (x) = (x + 1) (3x - 5)* atx = 1. [4 marks] f ' ( x ) = 2 ( x + 1 ) ( 1 ) + ( * + 1 ) 2 . 4 ( 3 x - 5 ) 3 ( 3 ) f ' ( * ) = 2 ( * +1 ) + 12 ( x + 1 ) ? ( 3 x - 5 ) 3 f' ( x ) = 2 ( 1 + 1 ) + 12 ( 1 + 1 ) 2 ( 3 ( 1 ) - 5 ) 3 25. If y = su and u = 4V(x + 1) , find when x = 3. [4 marks]