Tính nhanh: 17/19 × (-8)/13 + 17/13 × 5/19 + 17/19 02/12/2021 Bởi Mary Tính nhanh: 17/19 × (-8)/13 + 17/13 × 5/19 + 17/19
`17/19 . (-8)/13 + 17/13 . 5/19 + 17/19` `=17/19 .[(-8)/13 + 1] + 17/13 . 5/19` `=17/19 . 5/13 + 17/13 . 5/19` `=85/247 + 85/247` `=170/247` ~ HỌC TỐT ~ Bình luận
Đáp án: $\dfrac{170}{247}$ Giải thích các bước giải: $\dfrac{17}{19}\cdot\dfrac{-8}{13}+\dfrac{17}{13}\cdot\dfrac{5}{19}+\dfrac{17}{19}$ $=\dfrac{17}{19}\cdot\dfrac{-8}{13}+\dfrac{17}{19}\cdot\dfrac{5}{13}+\dfrac{17}{19}$ $=\dfrac{17}{19}(\dfrac{-8}{13}+\dfrac{5}{13}+1)$ $=\dfrac{17}{19}\cdot\dfrac{-8+5+13}{13}$ $=\dfrac{17}{19}\cdot\dfrac{10}{13}$ $=\dfrac{170}{247}$ Bình luận
`17/19 . (-8)/13 + 17/13 . 5/19 + 17/19`
`=17/19 .[(-8)/13 + 1] + 17/13 . 5/19`
`=17/19 . 5/13 + 17/13 . 5/19`
`=85/247 + 85/247`
`=170/247`
~ HỌC TỐT ~
Đáp án: $\dfrac{170}{247}$
Giải thích các bước giải:
$\dfrac{17}{19}\cdot\dfrac{-8}{13}+\dfrac{17}{13}\cdot\dfrac{5}{19}+\dfrac{17}{19}$
$=\dfrac{17}{19}\cdot\dfrac{-8}{13}+\dfrac{17}{19}\cdot\dfrac{5}{13}+\dfrac{17}{19}$
$=\dfrac{17}{19}(\dfrac{-8}{13}+\dfrac{5}{13}+1)$
$=\dfrac{17}{19}\cdot\dfrac{-8+5+13}{13}$
$=\dfrac{17}{19}\cdot\dfrac{10}{13}$
$=\dfrac{170}{247}$