Calcule ou simplifique a fração 6!.4!/5!.3!=

a)4/9+1/2=

4•2/9•2=

4•2/9•2+1•9/2•9=

8/18+9/18=

8+9/18=

17/18

b)6/7-2/7=

6-2/7=

4/7

c)21/16+5/16=

21+5/16=

26/16=

13/8

d)7/5-3/4=

7•4/5•4-3•5/4•5=

28/20-15/20=

28-15/20=

13/20

e)6/4+5/3=

3/2+5/3=

3•3/2•3+5•2/3•2=

9/6+10/6=

9+10/6=

19/6

Espero ter ajudado!