Toán Tính nhanh: B= 2/3 + 2/8 + 2/15 + 2/24 + 2/35 + 2/48 + 2/63 + 2/80 20/10/2021 By Everleigh Tính nhanh: B= 2/3 + 2/8 + 2/15 + 2/24 + 2/35 + 2/48 + 2/63 + 2/80
B= 2/3 + 2/8 + 2/15 + 2/24 + 2/35 + 2/48 + 2/63 + 2/80 B=$\frac{2}{3}$ + $\frac{2}{15}$ + $\frac{2}{24}$ + $\frac{1}{24}$ + $\frac{2}{8}$ + $\frac{2}{80}$ + $\frac{2}{35}$ + $\frac{2}{63}$ B=$\frac{10}{15}$ + $\frac{2}{15}$ + $\frac{2}{24}$ + $\frac{1}{24}$ + $\frac{10}{40}$ + $\frac{1}{40}$ + $\frac{2}{35}$ + $\frac{2}{63}$ B=$\frac{12}{15}$ + $\frac{1}{8}$ + $\frac{11}{40}$ + $\frac{2}{35}$ + $\frac{2}{63}$ B=$\frac{1}{8}$ + $\frac{11}{40}$ + $\frac{12}{15}$ +$\frac{2}{35}$ + $\frac{2}{63}$ B=$\frac{2}{5}$ + $\frac{12}{15}$ +$\frac{2}{35}$ + $\frac{2}{63}$ B=$\frac{44}{35}$ + $\frac{2}{63}$ B=$\frac{58}{45}$ Trả lời
Đáp án: Giải thích các bước giải: $B=\dfrac{2}{3}+\dfrac{2}{8}+\dfrac{2}{15}+\dfrac{2}{24}+\dfrac{2}{35}+\dfrac{2}{48}+\dfrac{2}{63}+\dfrac{2}{80}$ $ $ $B=\dfrac{2}{1.3}+\dfrac{2}{2.4}+\dfrac{2}{3.5}+\dfrac{2}{4.6}+\dfrac{2}{5.7}+\dfrac{2}{6.8}+\dfrac{2}{7.9}+\dfrac{2}{8.10}$ $ $ $B=(\dfrac{2}{1.3}+\dfrac{2}{3.5}+\dfrac{2}{5.7}+\dfrac{2}{7.9})+(\dfrac{2}{2.4}+\dfrac{2}{4.6}+\dfrac{2}{6.8}+\dfrac{2}{8.10})$ $ $ $B=(1-\dfrac{1}{9})+(\dfrac{1}{2}-\dfrac{1}{10})$ $ $ $=\dfrac{8}{9}+\dfrac{2}{5}$ $ $ $=\dfrac{40}{45}+\dfrac{18}{45}$ $ $ $=\dfrac{58}{45}$ Trả lời
B= 2/3 + 2/8 + 2/15 + 2/24 + 2/35 + 2/48 + 2/63 + 2/80
B=$\frac{2}{3}$ + $\frac{2}{15}$ + $\frac{2}{24}$ + $\frac{1}{24}$ + $\frac{2}{8}$ + $\frac{2}{80}$ + $\frac{2}{35}$ + $\frac{2}{63}$
B=$\frac{10}{15}$ + $\frac{2}{15}$ + $\frac{2}{24}$ + $\frac{1}{24}$ + $\frac{10}{40}$ + $\frac{1}{40}$ + $\frac{2}{35}$ + $\frac{2}{63}$
B=$\frac{12}{15}$ + $\frac{1}{8}$ + $\frac{11}{40}$ + $\frac{2}{35}$ + $\frac{2}{63}$
B=$\frac{1}{8}$ + $\frac{11}{40}$ + $\frac{12}{15}$ +$\frac{2}{35}$ + $\frac{2}{63}$
B=$\frac{2}{5}$ + $\frac{12}{15}$ +$\frac{2}{35}$ + $\frac{2}{63}$
B=$\frac{44}{35}$ + $\frac{2}{63}$
B=$\frac{58}{45}$
Đáp án:
Giải thích các bước giải:
$B=\dfrac{2}{3}+\dfrac{2}{8}+\dfrac{2}{15}+\dfrac{2}{24}+\dfrac{2}{35}+\dfrac{2}{48}+\dfrac{2}{63}+\dfrac{2}{80}$
$ $
$B=\dfrac{2}{1.3}+\dfrac{2}{2.4}+\dfrac{2}{3.5}+\dfrac{2}{4.6}+\dfrac{2}{5.7}+\dfrac{2}{6.8}+\dfrac{2}{7.9}+\dfrac{2}{8.10}$
$ $
$B=(\dfrac{2}{1.3}+\dfrac{2}{3.5}+\dfrac{2}{5.7}+\dfrac{2}{7.9})+(\dfrac{2}{2.4}+\dfrac{2}{4.6}+\dfrac{2}{6.8}+\dfrac{2}{8.10})$
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$B=(1-\dfrac{1}{9})+(\dfrac{1}{2}-\dfrac{1}{10})$
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$=\dfrac{8}{9}+\dfrac{2}{5}$
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$=\dfrac{40}{45}+\dfrac{18}{45}$
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$=\dfrac{58}{45}$