а) 3/14-9/17-8/17+1/14=-5/7 3/14+1/14=4/14=2/7 -9/17-8/17=-1 -1+2/7=-5/7 б) 9/19-4/5-3/5+10/19=-2/5 9/19+10/19=19/19=1 -4/5-3/5=-7/5=-1 2/5 1-1 2/5=-2/5