1) (7-56/36: 49/6)*6/7= 2) 4/15*(-5/8)+3/4*(-4/9)= 3) 72/73*34/65+72/73*39/65= 4) -1/4*8/6-7/18*9/21= 5) (6/5-2/3)*1/2= /-это дрбь * --это умножение , заранее .

)
(7-56/36:49/6)*6/7=
=(7-56/36*6/49)*6/7=(7-8/42)*6/7=
=(6 42/42-8/42)*6/7=6 34/42*6/7=286/42*6/7=
=286/49=
2)
4/15*(-5/8)+3/4*(-4/9)=-1/6+(-1/3)=-1/6+(-2/6)=
=-3/6=-1/3

3)
72/73*34/65+72/73*39/65=
4)
-1/4*8/6-7/18*9/21=-2/6-1/6=-3/6=-1/2
5)
(6/5-2/3)*1/2=(18/15-10/15)*1/2=
=8/15*1/2=4/15