(2/ х+3 - 5 /х) * х+3 /х+5
=(2x -5(x+3))/x(x+3)) *(x+3)/(x+5) =(2x -5x -15)*(x+3) /x(x+3)*(x+5) =(-3x -15) /x(x+5) = -3(x+5) /x(x+5) = -3/x