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
\(5\dfrac{5}{27}+\dfrac{7}{23}-0,5.\dfrac{5}{27}+\dfrac{16}{23}=\)
\(45\dfrac{1}{6}:\left(\dfrac{-4}{5}\right)-35\dfrac{1}{6}:\left(\dfrac{-4}{5}\right)=\)
\(25.\left(\dfrac{-1}{5}\right)^3+\dfrac{1}{5}-2.\left(\dfrac{-1}{2}\right)^2-\dfrac{1}{2}=\)
\(\left(3,1-2,5\right)-\left(-2,5-3,1\right)=\)
\(\dfrac{3}{8}.\dfrac{7}{5}-\dfrac{7}{5}.\dfrac{1}{8}+\dfrac{13}{20}=\)
CẦN GẤP NGAY VÀ LUÔN :)))))
So sánh:
\(M=\dfrac{3}{1^2.2^2}+\dfrac{5}{2^2.3^2}+\dfrac{7}{3^2.4^2}+...+\dfrac{17}{8^2.9^2}+\dfrac{19}{9^2.10^2}\) và 1
Các bn giải thích rõ cách làm giùm mình đc ko. Mình cảm ơn
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-\(\dfrac{1}{100}\)=\(\dfrac{99}{100}\)<\(\dfrac{100}{100}=1\)
Tính giá trị biểu thức :
a) \(5\dfrac{5}{27}+\dfrac{7}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)
b) \(\dfrac{3}{8}.27\dfrac{1}{5}-51.\dfrac{1}{5}.\dfrac{3}{8}+19\)
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
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
Thực hiện phép tính (bằng cách hợp lý nếu có thể)
a) \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
b) \(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}.33\dfrac{1}{3}\)
c) \(9.\left(-\dfrac{1}{3}\right)^3+\dfrac{1}{3}\)
d) \(15\dfrac{1}{4}:\left(-\dfrac{5}{7}\right)-25\dfrac{1}{4}\left(-\dfrac{5}{7}\right)\)
Sắp xếp các phân số sau theo thứ tự giảm dần: \(\dfrac{-5}{8};\dfrac{7}{10};\dfrac{-16}{14};\dfrac{23}{24};-1\)
CÁC BẠN GIẢI CHI TIẾT BÀI NÀY GIÚP MÌNH NHÉ! CẢM ƠN CÁC BẠN RẤT NHIỀU! 🤧🙏💖
MSC : `840`
`-5/8=-5.105/8.105=-525/840`
`7/10=7.84/10.84=588/840`
`-16/14=-16.60/14.60=-960/840`
`23/24=23.35/24.35=805/840`
`-1=-840/840`
Sắp xếp các phân số sau theo thứ tự giảm dần:
`805/840;588/840;-525/840;-840;-960/840`
Thực hiện phép tính
\(5\dfrac{5}{27}+\dfrac{7}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)
\(5\dfrac{5}{27}+\dfrac{7}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)
\(=\dfrac{140}{27}+\dfrac{7}{23}+\dfrac{1}{2}-\dfrac{5}{27}+\dfrac{16}{23}\)
\(=\dfrac{140}{27}-\dfrac{5}{27}+\dfrac{7}{23}+\dfrac{16}{23}+\dfrac{1}{2}\)
\(=5+1+\dfrac{1}{2}=6+\dfrac{1}{2}=\dfrac{13}{2}\)
Thực hiện phép tính: \(5\dfrac{27}{5}+\dfrac{27}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\).
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 ...
\(5\frac{27}{5}+\frac{27}{23}+0,5-\frac{5}{27}+\frac{16}{23}\)
=\(\frac{52}{5}+\frac{27}{23}+\frac{1}{2}-\frac{5}{27}+\frac{16}{23}\)
=(\(\frac{52}{5}+\frac{1}{2}\)) + (\(\frac{27}{23}+\frac{16}{23}\)) - \(\frac{5}{27}\)
=\(\frac{109}{10}+\frac{43}{23}-\frac{5}{27}\)
=12,58438003
hay \(\approx12,58\)
\(a,\dfrac{3}{5}+\dfrac{-5}{9}\)
\(b,\dfrac{1}{3}+\dfrac{-4}{3};\dfrac{4}{7}\)
\(c,-\dfrac{27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}\)
\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}\)
\(a,\dfrac{3}{5}+\dfrac{-5}{9}=\dfrac{27-25}{45}=\dfrac{2}{49}.\)
\(c,\dfrac{-27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}=\dfrac{-23}{23}+\dfrac{21}{21}+\dfrac{1}{2}=-1+1+\dfrac{1}{2}=\dfrac{1}{2}.\)
\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}=\dfrac{-8}{9}+\dfrac{1}{9}.\left(\dfrac{2}{9}+\dfrac{7}{9}\right)=\dfrac{-8}{9}+\dfrac{1}{9}.1=\dfrac{-8+1}{9}=\dfrac{-7}{9}.\)
\(\dfrac{29-x}{21}\)+\(\dfrac{27-x}{23}\)+\(\dfrac{25-x}{25}\)+\(\dfrac{23-x}{27}\)+\(\dfrac{21-x}{29}\)=\(\dfrac{(29-x+1}{21}\)+\(\dfrac{(27-x+1)}{23}\)+\(\dfrac{(25-x+1)}{25}\)+\(\dfrac{(23-x+1)}{21}\)=-5 +5
GIẢI nốt hộ mình với ạ