a: =321-21*[(2*27+16:32)-52]

=321-21*[2+0,5]

=321-21*2,5=268,5

b: \(=\dfrac{160}{17+\left[9\cdot5\left(14+8\right)\right]}\)

\(=\dfrac{160}{17+45\cdot22}=\dfrac{160}{1007}\)

c: =100*9:3^2=100

d: =2*27+143:(36-25)

=54+143:11

=54+13=67

3:

28/32=21/24

6/15=18/45

11/13=121/143

2:

7/2>4/79

27/9>2

51/17=3/1

= 1324x( 65+ 52 - 17 )

= 1324x100

= 132400

a) 1324 x 65 + 1324 x 52 - 17 x 1324

= 1324 x (65 + 52 - 17)

= 1324 x 100

= 132400.

b) 25 x 32 x 2 x 4

= (25 x 4) x (32 x 2)

= 100 x 64

= 6400.

=132400

a) 135 - ( x + 32 ) = 80

x + 32 = 135 - 80

x + 32 = 55

x = 55 - 32

x = 23

b)( x - 17 ) + 52 = 158

x - 17 = 158 - 52

x - 17 = 106

x = 106 + 17

x = 123

c x : 17 + 83 = 297

x : 17 = 297 - 83

x : 17 = 214

x = 214 x 17 

x = 3638

d) 9052: x - 56  = 17

9052 : x = 17 + 56

9052 : x = 73

x = 9052 : 73

x = \(\frac{1004}{17}\)

a)23

b)123

c)3638

d)1004/17

ai giúp với!!

Bài 1:

a. 31.72 - 31.70 - 31.2

= 31.(72-70-2)

= 31.0 = 0

b. 25. ( 32 + 47 ) - 32. ( 25 + 47 )

= 25.32 + 25.47 - 32.25 - 32.47

= (25.32 - 32.25) + 25.47 -32.47

= 0 + 47.( 25-32)

= 47.(-7) = -329

c. [ 3. ( - 2 ) - ( - 8 ) ] . ( - 7 ) - ( - 2 ) . ( - 5 )

= [ -6 + 8 ] . (-7)+2.(-5)

= 2. [(-7)+(-5) ]

= 2.(-12) = -24

d. ( - 3 ) ^ 2 + 3 ^ 3 - ( - 3 ) ^ 0

= 9 + 27 - 1

= 35

Đây là cách mình làm thôi. Có j sai thì bạn thông cảm nha...

Bài 1:

a. 31.72 - 31.70 -31.2

=31.(72-70-2)

=31.0

=0

b. 25. (32+47) -32 .(25+47)

=25.79 -32. 72

= 1975 -2304

= -329

c,[ 3.(-2)-(-8) ].(-7) - (-2) . (-5)

=[3.(-2)+8].(-7)+2.(-5)

=[(-6)+8].(-7)+(-10)

= 2.(-7)+(-10)

= (-14)+(-10)

= (-24)

d.(-3)² + 3³ - (-3)⁰

= 9 + 27 +3⁰

= 36

Bài 2:

a. -2x -3 =15

-2x=15 +3

-2x =18

x = 18 : -2

x= -9

b. 5-4x =17

4x =5 -17

4x = -12

x = -12 : 4

x= -3

c. -2 / x-3 /=16 : (-2)

-2 /x - 3/= -8

/x-3 /= -8 : -2

/x-3/=4

=>x-3 =4 hoặc x - 3=-4

x=4+3 ; x= -4+3

x=7 ; x= -1

Vậy x=7 hoặc x= -1

d. (x-1)² =4

( x-1)²=2²

=> x - 1 = 2

x=2+1

x=3

Bài 3:GTNN của A=2017 nha bạn

Bài 4:

43⁴³ - 17¹⁷ = (........7) - (.......7)

= (.........0)

Vì 43 ⁴³ - 17¹⁷ có tận cùng bằng 0 => \(⋮\) cho 2

Bài 5:

52⁵² - 13⁵² = (.....6) - (......1)

= (......5)

Vì 52⁵² - 13⁵² có tận cùng bằng 5 =>\(⋮\) cho 5

*Lưu ý:mk áp dụng tính chất Chữ số tận cùng.

sao ko tu lam

\(\text{1.(15+37)+(52-17-37)}\\ =15+37+52-17-37\\ =\left(15+52-17\right)+\left(37-37\right)\\ =50+0=50\)

\(\text{2.(21-32)-(-12+32)}\\ =21-32+12-32\\ =\left(21+12\right)+\left(-32-32\right)\\ =33+-64=-31\)

\(1,=15+37+52-17-37=50\)

\(2,=21-32+12-32=-40\)

\(\dfrac{93}{17}:x+\left[\dfrac{-4}{17}\right]:x+\dfrac{22}{7}:\dfrac{52}{3}=\dfrac{4}{11}\)

\(=>\left(\dfrac{93}{17}+\dfrac{-4}{17}\right):x+\dfrac{11}{26}=\dfrac{4}{11}\)

\(=>\dfrac{89}{17}:x+\dfrac{11}{26}=\dfrac{4}{11}\)

\(=>\dfrac{89}{17}:x=\dfrac{4}{11}-\dfrac{11}{26}\)

\(=>\dfrac{89}{17}:x=\dfrac{-17}{286}\)

\(=>x=\dfrac{89}{17}:\dfrac{-17}{286}\)

\(=>x=\dfrac{-25454}{289}=-88\dfrac{22}{289}\)

\(\dfrac{93}{17}:x-\dfrac{4}{17}:x+\dfrac{22}{7}:\dfrac{52}{3}=\dfrac{4}{11}\)

\(\Rightarrow\left(\dfrac{93}{17}-\dfrac{4}{17}\right):x+\dfrac{33}{182}=\dfrac{4}{11}\)

\(\Rightarrow\dfrac{89}{17}:x=\dfrac{365}{2002}\)

\(\Rightarrow x=\dfrac{178178}{6205}\)

Ta có: \(\dfrac{93}{17}:x+\dfrac{-4}{17}:x+\dfrac{22}{7}:\dfrac{52}{3}=\dfrac{4}{11}\)

\(\Leftrightarrow\dfrac{89}{17}:x=\dfrac{365}{2002}\)

hay \(x=\dfrac{178178}{6205}\)

\(B=3+3^2+3^3+3^4+...+3^{2009}+3^{2010}\)

\(=\left(3+3^2\right)+\left(3^3+3^4\right)+...+\left(3^{2009}+3^{2010}\right)\)

\(=3\left(1+3\right)+3^3\left(1+3\right)+...+3^{2009}\left(1+3\right)\)

\(=4.\left(3+3^3+...+3^{2009}\right)\)

⇒ \(B\) ⋮ 4

b: \(C=5\left(1+5+5^2\right)+...+5^{2008}\left(1+5+5^2\right)=31\cdot\left(5+...+5^{2008}\right)⋮31\)

(93/17+-4/17) : x + 33/182=4/11

89/17 : x = 4/11 + 33/182

89/17 : x = Sia đề