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H9
HT.Phong (9A5)
CTVHS
14 tháng 8 2023
\(50\%+\dfrac{1}{2}+\dfrac{1}{7}\times\dfrac{2}{5}+\dfrac{1}{7}\times\dfrac{3}{5}\)
\(=\dfrac{1}{2}+\dfrac{1}{2}+\dfrac{2}{35}+\dfrac{3}{35}\)
\(=1+\dfrac{5}{35}\)
\(=1+\dfrac{1}{7}\)
\(=\dfrac{8}{7}\)
ND
Nguyễn Đức Trí
VIP
14 tháng 8 2023
\(50\%+\dfrac{1}{2}+\dfrac{1}{7}x\dfrac{2}{5}+\dfrac{1}{7}x\dfrac{3}{5}\)
\(=\dfrac{1}{2}+\dfrac{1}{2}+\dfrac{1}{7}x\left(\dfrac{2}{5}+\dfrac{3}{5}\right)\)
\(=1+\dfrac{1}{7}x1\)
\(=\dfrac{7}{7}+\dfrac{1}{7}=\dfrac{8}{7}\)
KV
14 tháng 8 2023
50% + 1/2 + 1/7 × 2/5 + 1/7 × 3/5
= 1/2 + 1/2 + 1/7 × (2/5 + 3/5)
= 1 + 1/7 × 1
= 1 + 1/7
= 7/7 + 1/7
= 8/7
PT
0
XO
13 tháng 8 2020
a) 563 x 23 + 23 x 28 - 23
= 23 x (563 + 28 - 1)
= 23 x 600
= 19200
b) \(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}-1\frac{2}{5}=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)-\frac{7}{5}=2-\frac{7}{5}=\frac{3}{5}\)
c) \(\left(1-\frac{1}{2}\right)\times\left(1-\frac{1}{3}\right)\times\left(1-\frac{1}{4}\right)\times...\times\left(1-\frac{1}{10}\right)=\frac{1}{2}\times\frac{2}{3}\times\frac{3}{4}\times....\times\frac{9}{10}\)
\(=\frac{1\times2\times3\times...\times9}{2\times3\times4\times...\times10}=\frac{1}{10}\)
d) \(\frac{2}{7}\times\frac{3}{9}+\frac{2}{7}\times\frac{2}{3}=\frac{2}{7}\times\left(\frac{3}{9}+\frac{2}{3}\right)=\frac{2}{7}\times1=\frac{2}{7}\)
NH
13 tháng 8 2020
a ) \(563\cdot23+23\cdot28-23\)
\(=23\cdot\left(563+28-1\right)\)
\(=23\cdot600\)
\(=19200\)
b ) \(\frac{7}{11}+\frac{3}{4}+\frac{4}{11}+\frac{1}{4}-1\frac{2}{5}=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)-\frac{7}{5}=2-\frac{7}{5}=\frac{3}{5}\)
c ) \(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot...\cdot\left(1-\frac{1}{10}\right)=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot...\cdot\frac{9}{10}\)
\(=\frac{1\cdot2\cdot3\cdot...\cdot9}{2\cdot3\cdot4\cdot...\cdot10}=\frac{1}{10}\)
d ) \(\frac{2}{7}\cdot\frac{3}{9}+\frac{2}{7}\cdot\frac{2}{3}=\frac{2}{7}\cdot\left(\frac{3}{9}+\frac{2}{3}\right)=\frac{2}{7}\cdot1=\frac{2}{7}\)
DQ
1
AD
21 tháng 7 2021
a)\(\frac{4}{5}-\frac{1}{4}+\frac{3}{10}\)
\(=\frac{16}{20}-\frac{5}{20}+\frac{6}{20}\)
\(=\frac{17}{20}\)
b) \(\frac{2}{5}:\left(1-\frac{1}{10}\right)\)
\(=\frac{2}{5}:\frac{9}{10}\)
\(=\frac{4}{9}\)
c)\(\frac{7}{8}\times\frac{4}{9}+\frac{1}{14}:\frac{5}{14}\)
\(=\frac{7}{18}+\frac{1}{5}\)
\(=\frac{53}{90}\)
d)\(\frac{2}{7}\times\frac{3}{11}+\frac{2}{7}\times\frac{8}{11}\)
\(=\frac{2}{7}\times\left(\frac{3}{11}+\frac{8}{11}\right)\)
\(=\frac{2}{7}\times1=\frac{2}{7}\)
e) \(12+\left(16-11\right)\times4\)
\(=12+20=32\)
f)\(2\frac{3}{7}+1\frac{4}{7}\)
\(=\frac{17}{7}+\frac{11}{7}\)
\(=4\)
g)\(\frac{2}{3}\times\frac{4}{5}+\frac{1}{5}:\frac{9}{11}\)
\(=\frac{8}{15}+\frac{11}{45}\)
\(=\frac{7}{9}\)
h)\(\left(6,2:2+3,7\right):0,2\)
\(=\left(3,1+3,7\right):0,2\)
\(=6,8:0,2=34\)
#H
AH
Akai Haruma
Giáo viên
6 tháng 9 2023
Lời giải:
$\frac{4}{7}\times \frac{3}{5}\times \frac{7}{4}\times 20\times \frac{5}{36}$
$=(\frac{4}{7}\times \frac{7}{4})\times (\frac{3}{5}\times \frac{5}{36})\times 20$
$=1\times \frac{1}{12}\times 20=\frac{20}{12}=\frac{5}{3}$
22 tháng 10 2020
3/7x3/13+3/7:13/10+6/14
=3/7x3/13+3/7x10/13+6/14
=3/7x(3/13+10/13)+6/14
=3/7x1+6/14
=3/7+6/14
=3/7+3/7
=6/7
22 tháng 10 2020
Đề:...........
= 3/7 x 3/13 + 3/7 x 10/13 + 3/7
= 3/7 x (3/13 + 10/13 + 1)
= 3/7 x ( 1 + 1 )
= 3/7 x 2
= 6/7
\(\dfrac{2}{5}+\dfrac{3}{7}\)=\(\dfrac{14}{35}\)+\(\dfrac{15}{35}\)=\(\dfrac{29}{35}\)
2/5+1/7x3=2/5+3/7
=14/35+15/35=29/35