$\dfrac{ 14 }{ 29 } $ $ × $ $\dfrac{ 15 }{ 41 } $ $ + $ $\dfrac{ 14 }{ 29 } $ $ × $ $\dfrac{ 13 }{ 41 } $ $ + $ $\dfrac{ 28 }{ 41 } $ $ × $ $\dfrac{ 1

Đáp án:

` 14/29 \times 15/41 + 14/29 \times 13/41 + 28/41 \times 15/29`

` = 14/29 \times ( 15/41 + 13/41) + 28/41 \times 15/29`

` = 14/29 \times 28/41 + 28/41 \times 15/29`

` = 28/41 \times (14/29 + 15/29)`

` = 28/41 \times 29/29`

` = 28/41 \times 1`

` = 28/41`