2-6/13÷9/26 = 2- (6/13)×(26/9)=2- 4/3=2/3.(1/3+1/4)×36 =(1/3)×36 +(1/4)×36 =12+9=21.6/7×(4/5-2/3)÷1/5=(6/7)×(4/5 - 2/3)×5=(6/7)×(4 - 10/3)=(6/7)×(2/3)=4/7.3/4-3/4×4/7+9/7=(3/4)×(1- 4/7）...