b: \(8^{10}-8^9-8^8=8^8\left(8^2-8-1\right)=8^8\cdot55⋮55\)

c: 5^5-5^4+5^3

=5^3(5^2-5+1)

=5^3*21 chia hết cho 7

e:

72^63=(3^2*2^3)^63=3^126*2^189

 \(24^{54}\cdot54^{24}\cdot10^2=2^{162}\cdot3^{54}\cdot3^{72}\cdot2^{24}\cdot2^2\cdot5^2\)

\(=2^{188}\cdot3^{136}\cdot5^2\) chia hết cho 3^126*2^189

=>ĐPCM

g: \(=\left(3^4\right)^7-\left(3^3\right)^9-3^{26}\)

\(=3^{26}\left(3^2-3-1\right)=5\cdot3^{26}=5\cdot9\cdot3^{24}⋮5\cdot9=45\)

a) Ta có: \(\dfrac{7}{36}-\dfrac{8}{-9}+\dfrac{-2}{3}\)

\(=\dfrac{7}{36}+\dfrac{32}{36}+\dfrac{-24}{36}\)

\(=\dfrac{15}{36}=\dfrac{5}{12}\)

b) Ta có: \(\dfrac{-3}{8}\cdot\dfrac{1}{6}+\dfrac{-3}{8}\cdot\dfrac{5}{6}+\dfrac{-10}{16}\)

\(=\dfrac{-3}{8}+\dfrac{-10}{16}\)

\(=\dfrac{-6+\left(-10\right)}{16}=\dfrac{-16}{16}=-1\)

đăng từng bài rồi mình giải cho nha

Câu 3,5⁷-5⁶+5⁵=5⁵.5²-5⁵.5+5⁵=5⁵.(5²-5+1)=5⁵.21 chia hết cho 21

Câu:4:7⁶+7⁵-7⁴=7⁴.7²+7⁴.7-7⁴=7⁴.(7²+7-1)=7⁴.55=7⁴.11.5=7³.7.11.5=7³.77.5 chia hết cho 77

Các câu khác tương tự

bạn biết làm hết rồi, chỉ còn câu 2 chưa làm được đúng ko, vậy mình làm cho nhé, nhưng mà mình nghĩ là đề là 81 chứ ko phải 84 đâu

\(81^7-27^9-9^{13}=\left(3^4\right)^7-\left(3^3\right)^9-\left(3^2\right)^{13}=3^{28}-3^{27}-3^{26}=3^{25}\left(3^3-3^2-3\right)=3^{25}.15\) chia hết cho 15

Vậy 81⁷-27⁹-9¹³ chia hết cho 15 (đpcm)

3: \(=5^5\left(5^2-5+1\right)=5^2\cdot21⋮21\)

4: \(=7^4\left(7^2+7-1\right)=7^4\cdot55=7^3\cdot5\cdot77⋮77\)

5: \(=\left(2^{26}+2^{25}-2^{24}\right)=2^{24}\left(2^2+2-1\right)=2^{24}\cdot5⋮5\)

a)

\(\dfrac{48}{92}=\dfrac{48:4}{92:4}=\dfrac{12}{23}\)
\(\dfrac{36}{69}=\dfrac{36:3}{69:3}=\dfrac{12}{23}\)
Ta có: 
Mẫu số chung 2 phân số: 23
Vì \(12=12\) nên \(\dfrac{12}{23}=\dfrac{12}{23}\)
Vậy \(\dfrac{48}{92}=\dfrac{36}{69}\)

b)

\(\dfrac{3}{5}+\dfrac{4}{7}+\dfrac{7}{8}=\dfrac{573}{280}\)

Ta có: 
Mẫu số chung 2 phân số: 280
\(\dfrac{3}{1}=\dfrac{3*280}{1*280}=\dfrac{840}{280}\)
Vì \(573< 840\) nên \(\dfrac{573}{280}< \dfrac{840}{280}\)
Vậy \(\dfrac{573}{280}< \dfrac{3}{1}\)

c)
Ta có: 
Mẫu số chung 2 phân số: 10
\(\dfrac{2}{5}=\dfrac{2*2}{5*2}=\dfrac{4}{10}\)
Vì \(1< 4\) nên\(\dfrac{1}{10}< \dfrac{4}{10}\)
Vậy \(\dfrac{1}{10}< \dfrac{2}{5}\)

d)
\(\dfrac{4}{10}=\dfrac{4:2}{10:2}=\dfrac{2}{5}\)
Ta có: 
Mẫu số chung 2 phân số: 5
Vì \(2=2\) nên \(\dfrac{2}{5}=\dfrac{2}{5}\)
Vậy \(\dfrac{4}{10}=\dfrac{2}{5}\)

Hãy quy đồng hộ mình và đánh dấu nha 

1x2x3x4x5x6x7x8x9

2x3x4x5x6x7x8x9x10

=1/10

b)1/2*2/3*3/4*4/5*5/6*6/7*7/8*8/9*9/10

=1x2x3x4x5x6x7x8x9

  2x3x4x5x6x7x8x9x10

= 1

  10

\(\dfrac{5}{18}+\dfrac{7}{15}-\dfrac{7}{21}+\left(\dfrac{-10}{36}\right)+\dfrac{8}{15}+\dfrac{1}{3}-\dfrac{4}{9}\\ =\left(\dfrac{5}{18}+\dfrac{-10}{36}\right)+\left(\dfrac{7}{15}+\dfrac{8}{15}\right)+\left(\dfrac{-7}{21}+\dfrac{1}{3}\right)-\dfrac{4}{9} \\ =0+1+0-\dfrac{4}{9}=\dfrac{5}{9}\)

tinh hop li nhe

\(1.\) \(\dfrac{7}{36}-\dfrac{8}{-9}+\dfrac{-2}{3}=\dfrac{7}{36}+\dfrac{8}{9}-\dfrac{2}{3}=\dfrac{7+32-24}{36}=\dfrac{5}{12}.\)

\(2.\) \(\dfrac{-1}{2}+\dfrac{3}{7}-\dfrac{1}{9}+\dfrac{-7}{18}+\dfrac{4}{7}=\dfrac{-9-2-7}{18}+\dfrac{4+3}{7}=\dfrac{-18}{18}+\dfrac{7}{7}=-1+1=0.\)

\(3.\) \(-\dfrac{10}{3}+\dfrac{13}{10}-\dfrac{1}{6}+\dfrac{1}{10}=\dfrac{13+1}{10}+\dfrac{-20-1}{6}=\dfrac{14}{10}+\dfrac{-21}{6}=\dfrac{7}{5}-\dfrac{7}{2}=-\dfrac{21}{10}.\)

\(4.\) \(\dfrac{10}{17}-\dfrac{5}{13}-\left(-\dfrac{7}{17}\right)-\dfrac{8}{13}+\dfrac{11}{25}=\dfrac{10+7}{17}+\dfrac{-5-8}{13}+\dfrac{11}{25}=\dfrac{17}{17}-\dfrac{13}{13}+\dfrac{11}{25}=\dfrac{11}{25}.\)