Tính nhanh (nếu có thể):
a) \(5\dfrac{5}{27}+\dfrac{7}{23}+0,5.\dfrac{5}{27}+\dfrac{16}{23}\)
b) \(\dfrac{10^9.49^4}{14^8.25^5}\)
các bn ghi rõ cách giải giùm mình đcc ko, mình cảm ơn 
K
Khách
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Những câu hỏi liên quan
D
20 tháng 1 2022
M=\(\dfrac{3}{1^2.2^2}+\dfrac{5}{2^2.3^2}+\dfrac{7}{3^2.4^2}+...+\dfrac{17}{8^2.9^2}+\dfrac{19}{9^2.10^2}\)
=\(\dfrac{3}{1.4}+\dfrac{5}{4.9}+\dfrac{7}{9.16}+...+\dfrac{17}{64.81}+\dfrac{19}{81.100}\)
=\(1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{16}+...+\dfrac{1}{64}-\dfrac{1}{81}+\dfrac{1}{81}-\dfrac{1}{100}\)
=1-\(\dfrac{1}{100}\)=\(\dfrac{99}{100}\)<\(\dfrac{100}{100}=1\)
DN
17 tháng 6 2018
Dấu " / " là phân số nhé :
a) 5 5/27 + 7/23 + 0,5 - 5/27 + 16/23
= 140/27 + 7/23 + 1/2 - 5/27 + 16/23
= ( 140/27 - 5/27 ) + ( 7/23 + 16/23 ) + 1/2
= 5 + 1 + 1/2
= 6 + 1/2
= 13/2
b) 3/8 . 27 1/5 - 51 .1/5 . 3/8 + 19
= 3/8 . 136/5 - 51 . 1/5 . 3/8 + 19
= 3/8 . ( 136/5 - 1/5 ) - 51 + 19
= 3/8 . 27 - 51 + 19
= 81/8 - 52 + 19
= -183/8
DN
17 tháng 6 2018
Sorry nha mik sửa lại con B
b) 3/8 . 27 1/5 - 51 . 1/5 . 3/8 + 19
= 3/8 . 136/5 - 51/5 . 3/8 + 19
= 3/8 . ( 136/5 - 51/5 ) + 19
= 3/8 . 17 + 19
= 51/8 + 19
= 203/8
KM
1
LH
2 tháng 5 2017
\(5\dfrac{5}{27}+\dfrac{7}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)
\(=\dfrac{140}{27}+\dfrac{7}{23}+\dfrac{1}{2}-\dfrac{5}{27}+\dfrac{16}{23}\)
\(=\dfrac{140}{27}-\dfrac{5}{27}+\dfrac{7}{23}+\dfrac{16}{23}+\dfrac{1}{2}\)
\(=5+1+\dfrac{1}{2}=6+\dfrac{1}{2}=\dfrac{13}{2}\)
HH
22 tháng 6 2018
Giải:
\(5\dfrac{27}{5}+\dfrac{27}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)
\(=5+\dfrac{27}{5}+\dfrac{27}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)
\(=5+\dfrac{27}{5}+\dfrac{43}{23}+\dfrac{1}{2}-\dfrac{5}{27}\)
\(=\dfrac{52}{5}+\dfrac{43}{23}+\dfrac{1}{2}-\dfrac{5}{27}\)
\(=\dfrac{1411}{115}+\dfrac{1}{2}-\dfrac{5}{27}\)
\(=\dfrac{2937}{230}-\dfrac{5}{27}\)
\(\approx12,58\)
Vậy ...
27 tháng 3 2020
\(5\frac{27}{5}+\frac{27}{23}+0,5-\frac{5}{27}+\frac{16}{23}\)
=\(\frac{52}{5}+\frac{27}{23}+\frac{1}{2}-\frac{5}{27}+\frac{16}{23}\)
=(\(\frac{52}{5}+\frac{1}{2}\)) + (\(\frac{27}{23}+\frac{16}{23}\)) - \(\frac{5}{27}\)
=\(\frac{109}{10}+\frac{43}{23}-\frac{5}{27}\)
=12,58438003
hay \(\approx12,58\)
15 tháng 3 2022
\(a,\dfrac{3}{5}+\dfrac{-5}{9}=\dfrac{27-25}{45}=\dfrac{2}{49}.\)
\(c,\dfrac{-27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}=\dfrac{-23}{23}+\dfrac{21}{21}+\dfrac{1}{2}=-1+1+\dfrac{1}{2}=\dfrac{1}{2}.\)
\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}=\dfrac{-8}{9}+\dfrac{1}{9}.\left(\dfrac{2}{9}+\dfrac{7}{9}\right)=\dfrac{-8}{9}+\dfrac{1}{9}.1=\dfrac{-8+1}{9}=\dfrac{-7}{9}.\)
a) https://hoc247.net/hoi-dap/toan-7/thuc-hien-phep-tinh-5-5-27-7-23-0-5-5-27-16-23-faq218258.html
b) https://hoidap247.com/cau-hoi/1507941
b) \(\dfrac{10^9.49^4}{14^8.25^5}=\dfrac{\left(2.5\right)^9.\left(7^2\right)^4}{\left(7.2\right)^8.\left(5^2\right)^5}=\dfrac{2^9.5^9.7^6}{7^8.2^8.5^{10}}=\dfrac{2}{7.7.5}=\dfrac{2}{245}\)