4/3×7+4/7×11+4/11×15+4/15×19+4/19×23+4/23×27 22/08/2021 Bởi Camila 4/3×7+4/7×11+4/11×15+4/15×19+4/19×23+4/23×27
Đáp án: Giải thích các bước giải: $\dfrac{1}{3.7}+\dfrac{1}{7.11}+\dfrac{1}{11.15}+\dfrac{1}{15.19}+\dfrac{1}{19.23}+\dfrac{1}{23.27}$ $=\dfrac{1}{3}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{11}+\dfrac{1}{11}-\dfrac{1}{15}+\dfrac{1}{15}-\dfrac{1}{19}+\dfrac{1}{19}-\dfrac{1}{23}+\dfrac{1}{23}-\dfrac{1}{27}$ $=\dfrac{1}{3}-\left (\dfrac{1}{7}-\dfrac{1}{7}+\dfrac{1}{11}-\dfrac{1}{11}+\dfrac{1}{15}-\dfrac{1}{15}+\dfrac{1}{19}-\dfrac{1}{19}+\dfrac{1}{23}-\dfrac{1}{23} \right )-\dfrac{1}{27}$ $=\dfrac{1}{3}-\dfrac{1}{27}$ $=\dfrac{9}{27}-\dfrac{1}{27}$ $=\dfrac{8}{27}$ Chúc em học tốt. Bình luận
Đáp án : `8/{27}` Giải thích các bước giải: `4/{3.7} + 4/{7.11} + 4/{11.15} + 4/{15.19} + 4/{19.23} + 4/{23.27}` `= 1/3 – 1/7 + 1/7 – 1/{11} + 1/{11} – 1/{15} + 1/{15} – 1/{19} + 1/{19} – 1/{23} + 1/{23} – 1/{27}` `= 1/3 – 1/{27}` `= 8/{27}` Bình luận
Đáp án:
Giải thích các bước giải:
$\dfrac{1}{3.7}+\dfrac{1}{7.11}+\dfrac{1}{11.15}+\dfrac{1}{15.19}+\dfrac{1}{19.23}+\dfrac{1}{23.27}$
$=\dfrac{1}{3}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{11}+\dfrac{1}{11}-\dfrac{1}{15}+\dfrac{1}{15}-\dfrac{1}{19}+\dfrac{1}{19}-\dfrac{1}{23}+\dfrac{1}{23}-\dfrac{1}{27}$
$=\dfrac{1}{3}-\left (\dfrac{1}{7}-\dfrac{1}{7}+\dfrac{1}{11}-\dfrac{1}{11}+\dfrac{1}{15}-\dfrac{1}{15}+\dfrac{1}{19}-\dfrac{1}{19}+\dfrac{1}{23}-\dfrac{1}{23} \right )-\dfrac{1}{27}$
$=\dfrac{1}{3}-\dfrac{1}{27}$
$=\dfrac{9}{27}-\dfrac{1}{27}$
$=\dfrac{8}{27}$
Chúc em học tốt.
Đáp án : `8/{27}`
Giải thích các bước giải:
`4/{3.7} + 4/{7.11} + 4/{11.15} + 4/{15.19} + 4/{19.23} + 4/{23.27}`
`= 1/3 – 1/7 + 1/7 – 1/{11} + 1/{11} – 1/{15} + 1/{15} – 1/{19} + 1/{19} – 1/{23} + 1/{23} – 1/{27}`
`= 1/3 – 1/{27}`
`= 8/{27}`