Question

    Tính:
a) 6/7 + 7/8    b) 4/5 - 2/3      c) 2/3 x 4/9     d) 1/5 : 2/7

Answer 1

a) \(\dfrac{6}{7}+\dfrac{7}{8}=\dfrac{48}{56}+\dfrac{49}{56}=\dfrac{97}{56}\)

b) \(\dfrac{4}{5}-\dfrac{2}{3}=\dfrac{12}{15}-\dfrac{10}{15}=\dfrac{2}{15}\)

c) \(\dfrac{2}{3}.\dfrac{4}{9}=\dfrac{8}{27}\)

d) \(\dfrac{1}{5}:\dfrac{2}{7}=\dfrac{1}{5}.\dfrac{7}{2}=\dfrac{7}{10}\)

Answer 2

a: =48/56+49/56

=97/56

b: =12/15-10/15

=2/15

c: =(2*4)/(3*9)=8/27

d: =1/5*7/2=7/10

Answer 3

` 6/7 + 7/8 = 48/56 + 49/56 = 97/56`

 

` 4/5 - 2/3 = 12/15 - 10/15 = 2/15`

 

` 2/3 xx 4/9 = 8/27`

 

` 1/5 : 2/7 = 1/5 . 7/2 = 7/10`