= 16781312 + 1 = 16781313 

k tớ nhé 

k ết bạn nha 

li -ke cho tớ thật nhiều tuần sau li -ke lại cho 

A = 1+2+4+8+...+8192

A = 2⁰ + 2¹ + 2² + 2³ +...+2¹³

2A = 2¹+2²+2³+2⁴+...+2¹⁴

2A - A = 2¹⁴ - 2⁰

=> A = 2¹⁴ - 1

vạy bai fnayf 

là cách giải vậy à

cảm ơn các

bn nhé

Còn cái nịt, mua vip đi đã rồi giải cho

A = 1+2+4+8+...+8192

A = 2 0 + 2 1 + 2 2 + 2 3 +...+2 13

2A = 2 1+2 2+2 3+2 4+...+2 14

2A ‐ A = 2 14 ‐ 2 0

=> A = 2 14 ‐ 1

Đặt tổng trên = A

\(A=1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+...+\frac{1}{4096}+\frac{1}{8192}\)

\(A.2=2+1+\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2048}+\frac{1}{4096}\)

\(A.2-A=\left(2+1+\frac{1}{2}+\frac{1}{4}+...+\frac{1}{2048}+\frac{1}{4096}\right)-\left(1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+...+\frac{1}{4096}+\frac{1}{8192}\right)\)

\(A=2-\frac{1}{8192}=\frac{16383}{8192}\)
 

Đặt A = 1 + 1/2 + 1/4 + 1/8 + ... + 1/4096 + 1/8192

2A = 2 + 1 + 1/2 + 1/4 + ... + 1/2048 + 1/4096

2A - A = (2 + 1 + 1/2 + 1/4 + ... + 1/2048 + 1/4096) - (1 + 1/2 + 1/4 + 1/8 +... + 1/4096 + 1/8192)

A = 2 - 1/8192

A = 16383/8192

A=1+2+2^2+...+2^13

=>2A=2+2^2+...+2^14

=>2A-A=2^14-1

=>A=2^14-1

trình bày theo cách lớp 6 được không ạ?

\(\frac{\left(\frac{1}{2}\right)^2.2018-\left(\frac{1}{4}\right)^2.2017}{\frac{1}{4096}.\frac{1}{3}+2^{13}}\)

=

\(\frac{\left(\frac{1}{2}\right)^2.2018-\left(\frac{1}{4}\right)^6.2017}{\frac{1}{4096}.\frac{1}{3}+2^{13}}\)\(\Leftrightarrow\frac{\left(\frac{1}{4}\right).2018-\left(\frac{1}{4096}\right).2017}{\frac{1}{4096}.\frac{1}{3}+2^{13}}\)

Lược bỏ các số giống nhau đi ta được :

\(\frac{\left(\frac{1}{4}\right).2018.2017}{\frac{1}{3}+2^{13}}\Leftrightarrow\frac{\left(\frac{1}{4}\right).2018.2017}{\frac{1}{3}.8192}\Leftrightarrow\frac{\frac{1}{4}.4070306}{\frac{8192}{3}}\)

\(=\frac{1017576,5}{\frac{8192}{3}}\)

a) \(\left(8^{2019}-8^{2018}\right):\left(8^{2016}.8^2\right)\)

\(=8^{2018}\left(8-1\right):8^{2016+2}\)

\(=8^{2018}.7:8^{2018}=7\)

b) Em tham khảo link : Câu hỏi của ✽❤Girl cute❤✽ - Toán lớp 6 - Học toán với OnlineMath

em cảm ơn chị ạ!

\(A=49\frac{8}{23}-\left(5\frac{7}{32}+14\frac{8}{23}\right)\)

\(A=49\frac{8}{23}-5\frac{7}{32}+14\frac{8}{23}\)

\(A= \left(49\frac{8}{23}-14\frac{8}{23}\right)-5\frac{7}{32}\)

\(A=\left[\left(49-14\right)-\left(\frac{8}{23}-\frac{8}{23}\right)\right]-5\frac{7}{32}\)

\(A=\left[35-0\right]-5\frac{7}{32}\)

\(A=35-5\frac{7}{32}\)

\(A=\frac{953}{32}\)

\(B=71\frac{38}{45}-\left(43\frac{38}{45}-1\frac{17}{57}\right)\)

\(B=71\frac{38}{45}-\frac{36377}{855}\)

\(B=\frac{1670}{57}\)

\(C=\left(19\frac{5}{8}:\frac{7}{12}-13\frac{1}{4}:\frac{7}{12}\right):\frac{4}{5}\)

\(C=\left[\left(19\frac{5}{8}-13\frac{1}{4}\right):\frac{7}{12}\right]:\frac{4}{5}\)

\(C=\left[\frac{51}{8}:\frac{7}{12}\right]:\frac{4}{5}\)

\(C=\frac{153}{14}:\frac{4}{5}\)

\(C=\frac{765}{56}\)

\(D=\left[\left(\frac{10}{15}-\frac{2}{3}\right):\frac{1}{7}\right]\cdot0,15-\frac{1}{4}\)

\(D=\left[0:\frac{1}{7}\right]\cdot\frac{3}{20}-\frac{1}{4}\)

\(D=0\cdot\frac{3}{20}-\frac{1}{4}\)

\(D=0-\frac{1}{4}\)

\(D=-\frac{1}{4}\)

\(E=\frac{13}{30}+\frac{28}{45}\cdot2\frac{1}{2}-\left[\left(\frac{1}{2}+\frac{1}{3}\right):\frac{53}{90}\right]:\frac{50}{53}\)

\(E=\frac{13}{30}+\frac{28}{45}\cdot\frac{5}{2}-\left[\frac{5}{6}:\frac{53}{90}\right]:\frac{50}{53}\)

\(E=\frac{13}{30}+\frac{28}{45}\cdot\frac{5}{2}-\frac{75}{53}:\frac{50}{53}\)

\(E=\frac{13}{30}+\frac{14}{9}-\frac{3}{2}\)

\(\)\(E=\frac{22}{45}\)

CHUC BAN HOC TOT >.<