Question

Tính bằng cách thuận tiện nhất:4/5x3/7+4/5+6/7x6/7-4/5x4/14

Answer 1

4/5x3/7+4/5+6/7x6/7-4/5x4/14

= ( 3/7 + 6/7 + 4/14) x 4/5 

= 11/7 x 4/5 

= 44/35

Answer 2

44/35

Answer 3

4/5x3/7+4/5+6/7x6/7-4/5x4/14 ⇒ ( 3/7 + 6/7 + 4/14) x 4/5 ⇒ 11/7 x 4/5 ⇒ 44/35

Answer 4

\(\dfrac{4}{5}\times\dfrac{3}{7}+\dfrac{4}{5}+\dfrac{6}{7}\times\dfrac{6}{7}-\dfrac{4}{5}\times\dfrac{4}{14}=\dfrac{4}{5}\times\left(\dfrac{3}{7}-\dfrac{4}{14}\right)+\dfrac{4}{5}+\dfrac{6}{7}\times\dfrac{6}{7}=\dfrac{4}{5}\times\dfrac{1}{7}+\dfrac{4}{5}+\dfrac{6}{7}\times\dfrac{6}{7}=\dfrac{4}{5}\times\left(\dfrac{1}{7}+\dfrac{6}{7}\right)+\dfrac{4}{5}=\dfrac{4}{5}\times1+\dfrac{4}{5}=\dfrac{4}{5}+\dfrac{4}{5}=\dfrac{8}{5}\)