tính bằng cách thuận tiện nhất: 18 + 19 + 12 ---- ------ ----- 12 12 12

2 câu trả lời

$\dfrac{18}{12}$ + $\dfrac{19}{12}$ + $\dfrac{12}{12}$

= ($\dfrac{18}{12}$ + $\dfrac{12}{12}$) + $\dfrac{19}{12}$

= $\dfrac{30}{12}$ + $\dfrac{19}{12}$

= $\dfrac{49}{12}$

Đáp án:

`\frac{18}{12} +` `\frac{19}{12} +` `\frac{12}{12}`

` =` `(\frac{18}{12} + ` `\frac{12}{12}) +``\frac{19}{12}`

` =` `\frac{30}{12} +``\frac{19}{12}`

` =` `\frac{5}{2} +` `\frac{19}{12}`

` =` `\frac{30}{12} +` `\frac{19}{12}`

` =` `\frac{49}{12}`