a) 1; 3; 8; 16; 27; 41; 58

b) 1; 6; 11; 16; 21; 26

c) 1; 7; 8; 15; 23; 38; 61

có coppy gg ko dị

=) đùa đó tớ cx tik mà

Cá mập

Cá trê

mango mango mango mango mango mango mango mango mango mango mango

bạn ơi phần để bạn tự chỉnh nhé nó bị lỗi

A=111​+121​+...+701​

\(A = \left(\right. \frac{1}{11} + \frac{1}{12} + . . . + \frac{1}{20} \left.\right) + \left(\right. \frac{1}{21} + \frac{1}{22} + . . . + \frac{1}{30} \left.\right)\)

\(+ \left(\right. \frac{1}{31} + \frac{1}{32} + . . . + \frac{1}{40} \left.\right) + \left(\right. \frac{1}{41} + \frac{1}{42} + . . . + \frac{1}{50} \left.\right) + \left(\right. \frac{1}{51} + \frac{1}{52} + . . . + \frac{1}{60} \left.\right)\)

\(+ \left(\right. \frac{1}{61} + \frac{1}{62} + . . . + \frac{1}{70} \left.\right)\)

\(\Rightarrow A < \frac{1}{10} \cdot 10 + \frac{1}{20} \cdot 10 + \frac{1}{30} \cdot 10 + . . . + \frac{1}{60} \cdot 10\)

\(A < 1 + \frac{1}{2} + \frac{1}{3} + . . . + \frac{1}{6}\)

\(A < 1 + \frac{1}{2} + \frac{1}{3} + \frac{1}{6} + \left(\right. \frac{1}{4} + \frac{1}{5} \left.\right)\)

\(A < 2 + 0 , 45 < 2 , 5\)

gửi nhầm=xin lỗi

ngon thíiiiiiii

quá là nhiều tik 🤑🤑🤑😵