bạn ơi cho mk hỏi đề bài yêu cầu j thế ak

1: 243^5=(3^5)^5=3^25

3*27^8=3*(3^3)^8=3^25

=>243^5=3*27^8

6: 125^5=(5^3)^5=5^15

25^7=(5^2)^7=5^14

=>125^5>25^7(15>14)

5: 78^12-78^11=78^11(78-1)=78^11*77

78^11-78^10=78^10*77

mà 11>10

nên 78^12-78^11>78^11-78^10

a) 2 × 9 + 63 = 18 + 63 = 81

b) 24 : 4 + 44 = 6 + 44 = 50

c) 5 × 6 – 12 = 30 – 12 = 18

d) 3 × 7 – 16 = 21 – 16 = 5

1: =1-1+5-5+7-7+8-8=0

2: =14-23+5+14-5+23+17

=28+17=45

3: =12-12+9-9+14-44-3=-33

4: =22-8-8-12+4

=22-16-8

=-2

Bài \(1\)

\(1)\) \(1-5+7-8+4-1+5-7+8\)

\(=(1-1)+(5-5)+(7-7)+(8-8)\)

\(=0+0+0+0\)

\(=0\)

\(2)\) \(14-23+(5+14)-(5-23)+17\)

\(=14-23+5+14-5+23+17\)

\(=(14+14)+(23-23)+(5-5)+17\)

\(=28+17\)

\(=45\)

\(3)\) \(12-44+9-3+14-19-9-12\)

\(=(12-12)+(9-9)+(14-44)+3\)

\(=-30+3\)

\(=-33\)

\(4)\) \(22-(4-8+12)+(-8-12+4)\)

\(=22-4+8-12-8-12+4\)

\(=22+(4+4)+(8-8)+(-12-12)\)

\(=22-24\)

\(=-2\)

\(=\dfrac{195}{81}-\dfrac{12}{7}+\dfrac{44}{5}=\dfrac{8971}{945}\)

giúp mình với mọi người ơi, mình cần gấp :(

\(A=\left(\dfrac{5}{12}.\dfrac{21}{15}\right):\dfrac{1}{4}\)

\(=\dfrac{7}{12}:\dfrac{1}{4}\)

\(=\dfrac{28}{12}=\dfrac{7}{3}\)

\(B=\left(\dfrac{2}{7}:\dfrac{5}{4}\right).\left(\dfrac{5}{8}:2\right)\)

\(=\dfrac{8}{35}.\left(\dfrac{5}{8}:2\right)\)

\(=\dfrac{8}{35}.\dfrac{5}{16}\)

\(=\dfrac{1}{14}\)

\(C=\left(\dfrac{11}{15}.\dfrac{35}{44}\right).\left(\dfrac{1}{7}.\dfrac{4}{13}\right)\)

\(=\dfrac{7}{12}.\left(\dfrac{1}{7}.\dfrac{4}{13}\right)\)

\(=\dfrac{7}{12}.\left(\dfrac{1}{7}.\dfrac{4}{13}\right)\)

\(=\dfrac{7}{12}.\dfrac{4}{91}\)

\(=\dfrac{1}{39}\)

\(D=\left(\dfrac{7}{20}+\dfrac{11}{15}-\dfrac{15}{12}\right):\left(\dfrac{11}{20}-\dfrac{26}{45}\right)\)

\(=\left(\dfrac{13}{12}-\dfrac{15}{12}\right):\left(\dfrac{11}{20}-\dfrac{26}{45}\right)\)

\(=\dfrac{-1}{6}:\left(\dfrac{11}{20}-\dfrac{26}{45}\right)\)

\(=\dfrac{-1}{6}:\dfrac{-1}{36}\)

\(=6\)

1: 243^5=(3^5)^5=3^25

3*27^8=3*3^24=3^25=243^5

3: 3^300=27^100

2^200=4^100

mà 27>4

nên 3^300>2^200

4: 15^2=3^2*5^2

81^3*125^3=3^12*5^9

=>15^2<81^3*125^3

6: 125^5=5^15

25^7=5^14

mà 15>14

nên 125^5>25^7

Bạn ghi rõ đc hk ạ

\(a,\dfrac{4}{5}+\dfrac{1}{4}\times\dfrac{2}{5}\)

\(=\dfrac{4}{5}+\dfrac{1}{10}\)

\(=\dfrac{8}{10}+\dfrac{1}{10}\)

\(=\dfrac{9}{10}\)

\(---\)

\(b,\dfrac{7}{12}+\dfrac{3}{44}:\dfrac{3}{8}-\dfrac{1}{4}\)

\(=\left(\dfrac{7}{12}-\dfrac{1}{4}\right)+\dfrac{3}{44}\cdot\dfrac{8}{3}\)

\(=\left(\dfrac{7}{12}-\dfrac{3}{12}\right)+\dfrac{8}{44}\)

\(=\dfrac{4}{12}+\dfrac{8}{44}\)

\(=\dfrac{44}{132}+\dfrac{24}{132}\)

\(=\dfrac{68}{132}\)

\(=\dfrac{17}{33}\)

#\(Toru\)

A=15/8              D=27/40

B=4/15              E=1/14        

C=7/3                F=637/48