Nhanh lên ko ạ 

 Gợi ý:

a) \(\dfrac{1}{4}=0,25\)

\(\dfrac{1}{8}=0,125\)

\(\dfrac{1}{2}=0,5\)

b) $18,18=18$ x $1,01$

$1818,18=18$ x $101,01$

$25,25=25$ x $1,01$

$2525,25=25$ x $101,01$

Từ đây ta thấy hai phép nhân có kết quả bằng nhau.

a) \dfrac{1}{4}=0,2541​=0,25

\dfrac{1}{8}=0,12581​=0,125

\dfrac{1}{2}=0,521​=0,5

b) $18,18=18$ x $1,01$

$1818,18=18$ x $101,01$

$25,25=25$ x $1,01$

$2525,25=25$ x $101,01$

A = 0 , 25 × 7 + 0 , 25 2 0 , 4 × 5 2 − 2 5 A = 7 4 + 1 16 . 2 5 .25 − 2 5 A = 29 16 . 48 5 A = 87 5 = 17 2 5

B = 2 89 − 3 178 ⋅ 89 17 + 33 34 B = 4 178 − 3 178 . 89 17 + 33 34 B = 1 178 . 89 17 + 33 34 B = 1 34 + 33 34 = 1

Vậy A>B

a) 1,2+3.1,3=5,1

b) 0,2+2.0,5=1,2

a) \(2\sqrt{31}=\sqrt{4.31}=\sqrt{124}>\sqrt{100}=10\\\Rightarrow2\sqrt{31}>10\)

Bài 1: 

a) \(\sqrt{1.44}+3\sqrt{1.69}=1.2+3\cdot1.3=1.2+3.9=5.1\)

b) \(\sqrt{0.04}+2\cdot\sqrt{0.25}=0.2+2\cdot0.5=1.2\)

2:

=1-1+1-1=0

3:

a: =>34*(100+1)/2:a=17

=>a=101

b: =>5/3(x-1/2)=5/4

=>x-1/2=5/4:5/3=3/4

=>x=5/4

1a, \(\dfrac{2005}{2001}\) = 1+\(\dfrac{4}{2001}\); \(\dfrac{2009}{2005}\)=1+\(\dfrac{4}{2005}\)vì\(\dfrac{4}{2001}\)>\(\dfrac{4}{2005}\)nên\(\dfrac{2005}{2001}\)>\(\dfrac{2009}{2005}\)

1b,\(\dfrac{1313}{1515}\)=\(\dfrac{1313:101}{1515:101}\)= \(\dfrac{13}{15}\); \(\dfrac{131313}{151515}\)=\(\dfrac{131313:10101}{151515:10101}\)=\(\dfrac{13}{15}\)

Vậy \(\dfrac{13}{15}\)=\(\dfrac{1313}{1515}\)=\(\dfrac{131313}{151515}\)

Bài 1 :

\(\left(0.25\right)^5:\left(0,25\right)^3=\left(0,25\right)^2\)

b) ( -1/2) mũ 10 và bằng nhau

a) 5:0,5 = 5 x 2

52:0,5 = 52 x 2

b) 3:0,2 = 3x5

18:0,25 = 18x4

Sao bằng nha hết zậy?

a) 5:0,5 = 5 x 2

52:0,5 = 52 x 2

b) 3:0,2 = 3x5

18:0,25 = 18x4

Sao bằng nhau hết zậy?

a) 5:0,5 = 5 x 2

52:0,5 = 52 x 2

b) 3:0,2 = 3x5

18:0,25 = 18x4

a) 11/9 > 0

-17/36 < 0

⇒ 11/9 > -17/36

b) -13/4 < -12/4 (= -3)

-11/5 > -15/5 (= -3)

⇒ -13/4 < -11/5

c) Do 5,510 < 5,580

⇒ -5,510 > -5,580

d) -171,3 < 0

0,25 > 0

⇒ -171,3 < 0,25

a) 11/9 > 0

-17/36 < 0

⇒ 11/9 > -17/36

b) -13/4 < -12/4 (= -3)

-11/5 > -15/5 (= -3)

⇒ -13/4 < -11/5

c) Do 5,510 < 5,580

-> -5,510 > -5,580

d) -171,3 < 0

0,25 > 0

-> -171,3 < 0,25

Tính thuận tiện:

a, 46 : 24 + 8 : 24

= (46 + 8) : 24

 = 54 : 24

= \(\dfrac{9}{4}\)

b, 705 : 45 - 336 : 45

    =  (705 - 336): 45

   =  369 : 45

   = \(\dfrac{41}{5}\)

c,   2345 : 12,5 : 8

  = 2345 : (12,5 x 8)

= 2345 : 100

= 2,345

d, 25 : 5,6 x 14

 = 25 : 0,8 : 7 x 7 x 2

= 25 : 0,8 x 2

= 50 : 0,8

= 62,5

a)ta có :27⁶ = (3³)⁶ = 3¹⁸

16⁹ =(4²)⁹ =4¹⁸

Ta thấy : 3¹⁸ .4¹⁸ =(3.4)¹⁸=12¹⁸

12¹⁸=12¹⁸ =)3¹⁸. 4¹⁸ =12¹⁸

Hay 27⁶ .16⁹ =12¹⁸