đợi mk tí nha, nãy mk làm rồi nhma máy cập nhật lại nên mất bài =)

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

Ơ mọe

Sao biết rồi còn gửi câu hỏi

hì bạn cứ trả lời đi

\(10^8\times2^8=\left(10\times2\right)^8=20^8\)
\(10^8:2^8=\left(10:2\right)^8=5^8\)

10⁸ x 2⁸ = (10x2)⁸ = 20⁸

10⁸ :2⁸ = (10:2)⁸ = 5⁸

đề bài là gì vậy bạn

\(a,8\cdot\frac23:4\cdot\frac13-10=\frac{16}{3}:\frac43-10\)

\(=\frac{16}{3}\cdot\frac34-10=4-10=-6\)

\(b,\frac25+\frac35:\left(-\frac{9}{10}\right)-\frac13\)

\(=\frac25+\frac35\cdot\left(-\frac{10}{9}\right)-\frac13\)

\(=\frac25+\left(-\frac23\right)-\frac13=\frac25-\left(\frac23+\frac13\right)\)

\(=\frac25-1=\frac25-\frac55=-\frac35\)

\(c,-1,25\cdot\left(-4,1\right)\cdot8+0,2\)

\(=\left(-1,25\cdot8\right)\cdot\left(-4,1\right)+0,2\)

\(=\left(-10\right)\cdot\left(-4,1\right)+0,2\)

\(=41+0,2=41,2\)

a; 8\(\frac23\) : 4\(\frac13\) - 10

= \(\frac{26}{3}\) : \(\frac{13}{3}\) - 10

= \(\frac{26}{3}\times\frac{3}{13}\) - 10

= 2 - 10

= - 8

b; \(\frac25+\frac35\) : (- \(\frac{9}{10}\)) - \(\frac13\)

= \(\frac25\) + \(\frac35\) x (- \(\frac{10}{9}\)) - \(\frac13\)

= \(\frac25\) - \(\frac23\) - \(\frac13\)

= \(\frac25\) - (\(\frac23+\frac13\))

= \(\frac25\) - 1

= \(\frac25\) - \(\frac55\)

= - \(\frac35\)

c; -1,25 x (-4,1) x 8 + 0,2

= (1,25 x 8) x 4,1 + 0,2

= 10 x 4,1 + 0,2

= 41 + 0,2

= 41,2

b) \(\frac{2^9.4^{10}}{8^8}=\frac{2^9.\left(2^2\right)^{10}}{\left(2^3\right)^8}=\frac{2^9.2^{20}}{2^{24}}=\frac{2^{29}}{2^{24}}=2^5=32.\)

Chúc bạn học tốt!

\(a,8^{10}-8^9-8^8=8^8\left(8^2-8-1\right)=8^8\left(64-8-1\right)=8^8.55⋮55\left(\text{đpcm}\right)\)

\(b,81^7-27^9-9^{13}=3^{28}-3^{27}-3^{26}=3^{26}\left(3^2-3-1\right)=3^{26}.5=3^{24}\left(3^2.5\right)=3^{24}.45⋮45\left(\text{đpcm}\right)\)

hi

a) \(3^{7x-1}=815\)

\(\Leftrightarrow3^{7x}:3=815\)

\(\Leftrightarrow\left(3^7\right)^x:3=815\)

\(\Leftrightarrow2187^x=815.3\)

\(\Leftrightarrow2187^x=2445\)

\(\Rightarrow\) Không có x thoả mãn.

b) \(\left(-0,6\right)^5.x=\left(\dfrac{-3}{5}\right)^8\)

\(\Leftrightarrow x=\left(\dfrac{-3}{5}\right)^8:\left(-0,6\right)^5\)

\(\Leftrightarrow x=\left(-0,6\right)^8:\left(-0,6\right)^5\)

\(\Leftrightarrow x=\left(-0,6\right)^3\)

c) \(\left(0,5-x\right)^3=-8\)

\(\Leftrightarrow\left(0,5-x\right)^3=\left(-2\right)^3\)

\(\Rightarrow0,5-x=-2\)

\(\Leftrightarrow x=0,5+2\)

\(\Leftrightarrow x=2,5\).

Câu b hình như bạn làm sai rồi đó !