\(a,\dfrac{52}{32}=\dfrac{13}{8}\\ \dfrac{55}{65}=\dfrac{11}{13}\\ MSC:104\\ =>\dfrac{13}{8}=\dfrac{13.13}{8.13}=\dfrac{169}{104}\\ \dfrac{11}{13}=\dfrac{11.8}{13.8}=\dfrac{88}{104}\)

\(b,\dfrac{72}{64}=\dfrac{9}{8}\\ \dfrac{54}{81}=\dfrac{2}{3}\\ MSC:24\\ \dfrac{9}{8}=\dfrac{9.3}{8.3}=\dfrac{27}{24}\\ \dfrac{2}{3}=\dfrac{2.8}{3.8}=\dfrac{16}{24}\\ c,\dfrac{24}{36}=\dfrac{2}{3}\\ \dfrac{12}{30}=\dfrac{2}{5}\\ MSC:15\\ \dfrac{2}{3}=\dfrac{2.5}{3.5}=\dfrac{10}{15}\\ \dfrac{2}{5}=\dfrac{2.3}{3.5}=\dfrac{6}{15}\)

\(d,\dfrac{80}{40}=2\\ \dfrac{45}{63}=\dfrac{5}{7}\\ MSC:7\\ 2=\dfrac{14}{7}\\ e,\dfrac{150}{50}=3\\ \dfrac{100}{200}=\dfrac{1}{2}\\ MSC:2\\ 3=\dfrac{6}{2}\\ f,\dfrac{54}{81}=\dfrac{2}{3}\\ \dfrac{69}{93}=\dfrac{23}{21}\\ MSC:21\\ \dfrac{2}{3}=\dfrac{2.7}{3.7}=\dfrac{14}{21}\)

\(a.\dfrac{52}{32}\text{=}\dfrac{13}{8};\dfrac{55}{65}\text{=}\dfrac{11}{13}\)

\(\dfrac{13.13}{13.8}\text{=}\dfrac{169}{104};\dfrac{11.8}{13.8}\text{=}\dfrac{88}{104}\)

\(c.\dfrac{24}{36}\text{=}\dfrac{2}{3};\dfrac{12}{30}\text{=}\dfrac{2}{5}\)

\(\dfrac{2.5}{3.5}\text{=}\dfrac{10}{15};\dfrac{2.3}{5.3}\text{=}\dfrac{6}{15}\)

\(b.\dfrac{72}{64}\text{=}\dfrac{9.3}{8.3}\text{=}\dfrac{27}{24};\dfrac{54}{81}\text{=}\dfrac{2.8}{3.8}\text{=}\dfrac{16}{24}\)

\(d.\dfrac{80}{40}\text{=}\dfrac{2.63}{63}\text{=}\dfrac{126}{63};\dfrac{45}{63}\)

\(e.\dfrac{150}{50}\text{=}\dfrac{3.2}{2}\text{=}\dfrac{6}{2};\dfrac{100}{200}\text{=}\dfrac{1}{2}\)

\(f.\dfrac{54}{81}\text{=}\dfrac{2.31}{3.31}\text{=}\dfrac{62}{93};\dfrac{69}{93}\)

`a, 36 + 14 + 9`

`= 50 + 9`

`= 59`

`b, 51 + 12 + 18`

`=51 + 30`

`= 81`

`c, 65 + 9 + 5`

`= 70 + 9`

`= 79`

`d, 31 + 26 + 69`

`= 100 + 26`

`= 126`

a) 16 = 2⁴

42 = 2.3.7

ƯCLN(16; 42) = 2

ƯC(16; 42) = Ư(2) = {1; 2}

b) 16 = 2⁴

42 = 2.3.7

86 = 2.43

ƯCLN(16; 42; 86) = 2

ƯC(16; 42; 86) = Ư(2) = {1; 2}

c) 25 = 5²

75 = 3.5²

ƯCLN(25; 75) = 5² = 25

ƯC(25; 75) = Ư(25) = {1; 5; 25}

d) 25 = 5²

55 = 5.11

75 = 3.5²

ƯCLN(25; 55; 75) = 5

ƯC(25; 55; 75) = Ư(5) = {1; 5}

1)
a) \(34,2:36=0,95\)
b) \(36,18:18=2,01\)
c) \(5,05:25=0,202\)
d) \(17,25:75=0,23\)
2) 
a) \(75,52:32=2,36\)
b) \(4,68:13=0,36\)
c) \(81,6:34=2,4\)
d) \(134,4:42=3,2\)
3) 
a) \(882:36=24,5\)
b) \(78:24=3,25\)
c) \(3:15=0,2\)
d) \(15:75=0,2\)
4) 
a) \(3:75=0,04\)
b) \(750:300=2,5\)
c) \(390:12=32,5\)
d) \(54:24=2,25\)

D. 17
vì proton = electron

Số proton= số electron

\(\Rightarrow\)\(p=e=17e\)

Chọn D.

D

a) >

b) =

c) >

d) <

2/3>3/7

2/5=2/5

11/7>11/8

52/91<5/7

a ) >

b ) =

c)>

d)<

\(A=1+2+3+4......+2^{2010}\)

\(B=2^{2011-1}\)

\(B=2^{2011-1}=2.2.2.2......2=2^{2010}\)

\(=>A=1+2+3.....+2^{2010}>B=2^{2010}\)

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