Question

Tính = cách thuận tiện nhất :3/5 × 5/8 + 3/8 × 3/5=

Answer 1

\(=\dfrac{3}{5}x\left(\dfrac{5}{8}+\dfrac{3}{8}\right)=\dfrac{3}{5}x1=\dfrac{3}{5}\)

Answer 2

`3/5 xx 5/8 + 3/8 xx 3/5`

`= 3/5 xx (5/8 + 3/8)`

`= 3/5 xx 8/8`

`= 3/5 xx 1 `

`= 3/5`

Phương pháp: Chung đặt ra ngoài.

Answer 3

\(\dfrac{3}{5}\times\dfrac{5}{8}+\dfrac{3}{8}\times\dfrac{3}{5}=\dfrac{3}{5}\times\left(\dfrac{5}{8}+\dfrac{3}{8}\right)=\dfrac{3}{5}\times1=\dfrac{3}{5}\)