Question

Tính bằng cách thuận tiên nhất:

1/5 + 4/11 + 4/5 + 7/11 =

5/6 + 8/24 + 1/6 + 16/24 =

 

Answer 1

\(\dfrac{1}{5}+\dfrac{4}{11}+\dfrac{4}{5}+\dfrac{7}{11}=\left(\dfrac{1}{5}+\dfrac{4}{5}\right)+\left(\dfrac{4}{11}+\dfrac{7}{11}\right)=\dfrac{5}{5}+\dfrac{11}{11}=1+1=2\)

\(\dfrac{5}{6}+\dfrac{8}{24}+\dfrac{1}{6}+\dfrac{16}{24}=\dfrac{5}{6}+\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{2}{3}=\left(\dfrac{5}{6}+\dfrac{1}{6}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)=\dfrac{6}{6}+\dfrac{3}{3}=1+1=2\)

Answer 2

( 1/5+4/5)+ (4/11+7/11)

= 1+1=2

( 5/6+1/6)+ (8/24+16/24)

=1+1=2

Answer 3

a)\(=\left(\dfrac{1}{5}+\dfrac{4}{5}\right)+\left(\dfrac{4}{11}+\dfrac{7}{11}\right)=1+1=2\)

b)\(=\left(\dfrac{5}{6}+\dfrac{1}{6}\right)+\left(\dfrac{8}{24}+\dfrac{16}{24}\right)=1+1=2\)

Answer 4

\(\dfrac{1}{5}+\dfrac{4}{11}+\dfrac{4}{5}+\dfrac{7}{11}\\ =\left(\dfrac{1}{5}+\dfrac{4}{5}\right)+\left(\dfrac{4}{11}+\dfrac{7}{11}\right)\\ =1+1=2\\ \dfrac{5}{6}+\dfrac{8}{24}+\dfrac{1}{6}+\dfrac{16}{24}\\ =\left(\dfrac{5}{6}+\dfrac{1}{6}\right)+\left(\dfrac{8}{24}+\dfrac{16}{24}\right)\\ =1+1=2\)