ta có: \(8^{10}-8^9-8^8=8^8\left(8^2-8-1\right)\)
\(=8^8\cdot55\)
vậy \(\left(8^{10}-8^9-8^8\right)\) chia hết cho 55

(321 + 56) x 2 = 377 x 2 = 754

ta có: \(x\left(2x-\frac{4}{11}\right)=0\)
\(\Rightarrow\left[\begin{array}{l}x=0\\ 2x-\frac{4}{11}=0\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{l}x=0\\ 2x=\frac{4}{11}\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{l}x=0\\ x=\frac{4}{11}:2\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{l}x=0\\ x=\frac{2}{11}\end{array}\right.\)

chúc mừng bn!

ngta hỏi bạn Hải chứ đou hỏi bạn nam?

very difficult

hi

thì so coooool

1. What do you do?
2. Where does her father work?
3. Is she an accountant?
4. Where does John work?
5. Does he work in a company?

Ta có:
\(A=1\left(1+2\right)+2\left(2+2\right)+3\left(3+2\right)+\cdots+98\left(98+2\right)\)
\(A=\left(1\cdot1+1\cdot2\right)+\left(2\cdot2+2\cdot2\right)+\left(3\cdot3+3\cdot2\right)+\cdots+\left(98\cdot98+98\cdot2\right)\)
\(A=\left(1^2+2^2+3^2+\cdots+98^2\right)+2\left(1+2+3+\cdots+98\right)\)
Đặt \(B=1^2+2^2+3^2+\cdots+98^2\)
và \(C=1+2+3+\cdots+98\)
Ta có: \(B=1^2+2^2+3^2+\cdots+98^2\)
\(B=1\left(2-1\right)+2\left(3-1\right)+3\left(4-1\right)+\cdots+98\left(99-1\right)\)
\(B=\left(1\cdot2+2\cdot3+3\cdot4+\cdots+98\cdot99\right)-\left(1+2+3+\cdots+98\right)\)
\(\Rightarrow A=\left(1\cdot2+2\cdot3+3\cdot4+\cdots+98\cdot99\right)+\left(1+2+3+...+98\right)\)
Dặt \(D=1\cdot2+2\cdot3+3\cdot4+\cdots+98\cdot99\), tính tổng \(D\) :
\(D=1\cdot2+2\cdot3+3\cdot4+\cdots+98\cdot99\)
\(3D=1\cdot2\left(3-0\right)+2\cdot3\left(4-1\right)+3\cdot4\left(5-2\right)+\cdots+98\cdot99\left(100-97\right)\)
\(3D=\left(1\cdot2\cdot3-0\cdot1\cdot2\right)+\left(2\cdot3\cdot4-1\cdot2\cdot3\right)+\left(3\cdot4\cdot5-2\cdot3\cdot4\right)+\cdots+\left(98\cdot99\cdot100-97\cdot98\cdot99\right)\)
\(3D=98\cdot99\cdot100-0\cdot1\cdot2\)
\(3D=98\cdot99\cdot100\)
\(D=98\cdot33\cdot100\)
\(C=1+2+3+\cdots+98\)
\(C=\left(98+1\right)\cdot\frac{98}{2}\)
\(C=4851\)
Vậy \(A=D+C=98\cdot33\cdot100+4851=328251\)
Tích cho mik nha