Question

De_1/7restar _3/4
De 1/7 restar _4/5
De 4/9 restar 1/3
De 16/5 restar 7/3
Restar (1/5_3/8) de 1/12
Restar (2_3/4)de (_3/4+1)

Answer 1

1/7-3/4=  4 - 21  =  -17
                  28          28

  1/7- 4/5=    5- 28  = - 23
                      35             35

4/9  -  1/3=    4 - 3 =  1 
                         9       9

  16/5 -  7/3= 48 - 35 =   13      
                       15             15

1/12- (1/5-3/8)= 1 - (8-15) =  12 - (-21)  = 12+21 =  33
                          12     40          120                120    120
 

(_3/4+1) -  (2_3/4)= 7 - 11   =  -4    = -1 
                                  4   4          4