9⁹:9=43046721

tk nhé

xin đó

9⁹:9 = 9^9-1=9⁸

bằng chín mũ tam

\(\frac{-1}{5}\)

-1/5 . (9/8 + 16/32 - 12/46) - 9/17

= -1/5 . (9/8 + 1/2 - 6/23) - 9/17

= -1/5 . (9/8 + 4/8 - 6/23) - 9/17

= -1/5 . (13/8 - 6/23) - 9/17

= -1/5 . 251/184 - 9/17

= -251/920 - 9/17

= -4267/15640 - 8280/15640

= -12547/15640

18 con vịt

18 con vịt

9 con 

đúng ko

\(9^2.9^8\)

= \(9^{2+8}\)

=\(9^{10}\)

\(k\) \(minh\)\(nha\)

\(minh\)\(k\)\(bn\)\(day\)

9² x 9⁸ 

= 9^{2 + 8}

= 9¹⁰

ai k mk, mk k lại cho

mk ko có nói dối đâu

9² x 9⁸

= 9²⁺⁸

= 9¹⁰

#)Giải :

Đặt \(A=\frac{1}{5.6}+\frac{1}{6.7}+\frac{1}{7.8}+\frac{1}{8.9}+\frac{1}{9.10}\)

\(A=\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}+\frac{1}{9}-\frac{1}{10}\)

\(A=\frac{1}{5}-\frac{1}{10}\)

\(A=\frac{1}{10}\)

cho mk hỏi chút là tại sao ta lấy 1/5 - 1/6 r + 1/6....

\(A=\frac{1}{5\cdot6}+\frac{1}{6\cdot7}+\frac{1}{7\cdot8}+\frac{1}{8\cdot9}+\frac{1}{9\cdot10}\)

\(A=\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+...+\frac{1}{9}-\frac{1}{10}\)

\(A=\frac{1}{5}-\frac{1}{10}\)

\(A=\frac{2}{10}-\frac{1}{10}=\frac{1}{10}\)

=21 nha

\(\frac{9}{3}+9\times2=3+9\times2=3+18=21\)

\(\frac{9}{3}+9\times2\) = \(\frac{9}{3}+18=21\) 

9²

tk nhe

minh hoc roi

xin do

9^2=81

\(9^8:9^6=9^{8-6}=9^2=81\)

\(9\frac{5}{34}-12+5\)

\(9\frac{5}{34}=\frac{311}{34}\)

\(\Rightarrow9\frac{5}{34}-12+5\)

\(=\frac{311}{34}-12+5\)

\(=-\frac{97}{34}+5\)

\(=\frac{73}{34}\)

= \(\frac{69}{34}\)

Mk kb rùi đó , tk mk nha !

\(9\frac{5}{34}-12+5\)

\(=\frac{311}{34}-12+5\)

\(=-\frac{97}{34}+5\)

\(=\frac{73}{34}\)