Question

Bài 1: Tính

a. 1/5 + 7/3 + 6/5

b. 9/10 + 7/2 + 1/5

c. 9/2 - 1/5

d. 7/3 - 5/21

Answer 1

Bài 1: a) \(\dfrac{1}{5}+\dfrac{7}{3}+\dfrac{6}{5}\)

\(=\dfrac{3}{15}+\dfrac{35}{15}+\dfrac{18}{15}\)

= \(\dfrac{3+35+18}{15}=\dfrac{56}{15}\)

Answer 2

a. 1/5 + 7/3 + 6/5

= 3/15 + 35/15 + 18/15

= 3 + 35 + 18 / 15

= 56/15

b. 9/10 + 7/2 + 1/5

= 9/10 + 35/10 + 2/10

= 9 + 35 + 2 /10

= 46/10

c. 9/2 - 1/5

= 45/10 - 2/10

= 43/10

d. 7/3 - 5/21

= 49/21 - 5/21

= 44/21