15\16(5 1\3x-4\15 y)- 7\23(3 2\7x-2 4\21y)

15/16( 5 1/3x - 4/15y ) - 7/23( 3 2/7x - 2 4/21y ) = 15/16( 16/3x - 4/15y ) - - 7/23( 23/7x - 46/21y ) = 5x - 1/4y - x + 2/3y = 4x - 3/12y + 8/12y = 4x - 5/12y