Question

Tính giá trị biểu thức:

a) \(\dfrac{1}{3}-\dfrac{2}{15}+\dfrac{14}{15}\)

 

b) \(\dfrac{3}{5}+4-\dfrac{6}{7}\)

Answer 1

`1/3-2/15+14/15`

`=5/15-2/15+14/15`

`=17/15`

 

`3/5+4-6/7`

`=21/35+140/35-30/35`

`=131/35`

Answer 2

giúp mình với ạ, thanks!

Answer 3

`1/3- 2/15 + 14/15`

`= 5/15 -2/15 + 14/15`

`=(5-2+14)/15`

`= 17/15`

`--`

`3/5 + 4 -6/7`

`= 3/5 + 20/5 - 6/7`

`= 23/5 - 6/7`

`= 131/35`