А) (3,7 - 8,6) * (-3,1)-5,09=
-4,9*(-3,1)-5,09=15,19-5,09=10,1;////
б) 8,04 * (-3,2)-(-0,18) * (-0,4)=
-25,728+0,18*(-0,4)=
-25,728-0,072=-25,8;////
в) 9/14*(-2 1/3) + (-3 3/4) * 5/6=
9/14*(+7/3)-15/4*5/6=
3/2-25/8=12/8-25/8=-13/8=-1 5/8;///
г) (-1 5/9*2 1/7 + 1 7/12)*1 1/7=
(-14/9*15/7+19/12)*8/7=
(-10/3+19/12)*8/7=
(-40/12+19/12)*8/7=-21/12*8/7=-6/3=-2;///
№247 Выполните деление
а)56:(-8)=-7;///
б)-7,5:(-0,5)=15;///
в) -14,21:4,9=-2,9