А)-12/35*15/16= Б) 13/28:(-11/14)=
А) -12/35 * 15/16 = - (3*3)/(7*4) = - 9/28 б) 13/28 : (-11/14) = 13/28 * (-14/11) = - (13*1)/(2*11) = - 13/22