47.(59 - 71) - 71.( -59  - 47) + 72.59

=   47.59 - 47.71 + 71.59 + 71.47 + 72.59

=   (47.59 + 71.59 + 72.59 ) - (47.71 - 47.71)

= 59.(47 +  71 + 72) - 0

= 59.190

= 11210

47. (-12)-71.(-106)+72.59

=-564+7526+4248

=6962+4248

=11210

47. (-12)-71.(-106)+72.59

=-564-7526+4248

=-8087+4248

=-3839

Lời giải chi tiết:

=46+[72+59+11]

=46+262

=272

tính hơn nhanh nên ko có chắc đấp án đúng nha

46 + 72 + 46 + 59 + 46 + 11 = 280

Tk nha!!

46 + 72 + 46 + 59 + 46 + 11

= ( 46 + 46 + 46 ) + ( 72 + 59 + 11 )

= ( 46 × 3 ) + 142 

= 138 + 142 

= 280

2. Đặt \(x-1996=t\)

\(\Rightarrow\left(x-1996\right)^3+\left(x-1997\right)^3-1=t^3+\left(t-1\right)^2-1\)

\(=t^3+t^2-2t+1-1=t^3+t^2-2t=t\left(t^2+t-2\right)\)

\(=t.\left[\left(t^2-t\right)+\left(2t-2\right)\right]=t\left[t\left(t-1\right)+2\left(t-1\right)\right]\)

\(=t\left(t-1\right)\left(t+2\right)=\left(x-1996\right)\left(x-1996-1\right)\left(x-1996+2\right)\)

\(=\left(x-1996\right)\left(x-1997\right)\left(x-1994\right)\)

1. Đặt x² + 4x + 8 = y

bthuc ⇔ y² + 3xy + 2x²

          = y² + xy + 2xy + 2x²

          = ( xy + y² ) + ( 2x² + 2xy )

          = y( x + y ) + 2x( x + y )

          = ( x + y )( y + 2x )

          = ( x + x² + 4x + 8 )( x² + 4x + 8 + 2x )

          = ( x² + 5x + 8 )( x² + 6x + 8 )

          = ( x² + 5x + 8 )( x² + 2x + 4x + 8 )

          = ( x² + 5x + 8 )[ x( x + 2 ) + 4( x + 2 ) ]

          = ( x² + 5x + 8 )( x + 2 )( x + 4 )

2. Đặt t = x - 1996 

bthuc ⇔ t³ + ( t - 1 )² - 1

           = t³ + t² - 2t + 1 - 1

           = t³ + t² - 2t

           = t( t² + t - 2 )

           = t( t² - t + 2t - 2 )

           = t( t - 1 )( t + 2 )

           = ( x - 1996 )( x - 1996 - 1 )( x - 1996 + 2 )

           = ( x - 1996 )( x - 1997 )( x - 1994 )

3. 4( x² + 15x + 59 )( x² + 18x + 72 ) - 3x² < bó tay :)) >

\(41-\dfrac{72}{19-108:\left[59-2\left(3^2-11\cdot2\right)^2\right]}\)

\(=41-\dfrac{72}{19-108:\left[59-2\left(18-22\right)^2\right]}\)

\(=41-\dfrac{72}{19-108:\left[59-2\cdot16\right]}\)

\(=41-\dfrac{72}{19-108:27}\)

\(=41-\dfrac{72}{19-4}=41-\dfrac{72}{15}\)

=41-4,8

=36,2

\(41-72:\left\{19-108:\left[59-2.\left(3^2-11.2\right)^2\right]\right\}\)

\(=41-72:\left\{19-108:\left[59-2.\left(9-22\right)^2\right]\right\}\)

\(=41-72:\left\{19-108:\left[59-2.\left(-13\right)^2\right]\right\}\)

\(=41-72:\left\{19-108:\left[59-2.169\right]\right\}\)

\(=41-72:\left\{19-108:\left[59-338\right]\right\}\)

\(=41-72:\left\{19-108:-279\right\}\)

\(=41-72:\left\{19-\dfrac{-12}{31}\right\}\)

\(=41-72:\dfrac{601}{31}\)

\(=41-\dfrac{2232}{601}\)

\(=\dfrac{22409}{601}\)

45+59+82+34+72+65=375

45+59+82+34+72+65=357

nhớ qua k mk nha

SO CAN TIM LA: 

45 + 59 + 82 + 34 + 72 + 65 = 327 

Đap so: 327

a) x - ( 25 + 72 ) = 59 - 81

x - ( 25 + 72 ) = - 22

x - 97 = - 22

x = - 22 + 97

x = 75

b) 3x - ( - 15 ) = - 57 - 93

3x - ( - 15 ) = - 150

3x = - 150 + ( - 15 )

3x = - 165

x = - 165 : 3

x = -55

a) x-(25+72)=59-81

=> x-97=-22

=> x =-22+97

=> x = 75

=>

b) 3x-(-15) = -57-93

=>3x-(-15) = -150

=> 3x =(-150)+(-15)

=> 3x = -165

=> x = -165:3

=> x = -55

\(3^{x+2}-3^x=72\)

\(\Rightarrow3^x\cdot\left(3^2-1\right)=72\)

\(\Rightarrow3^x\cdot\left(9-1\right)=72\)

\(\Rightarrow3^x\cdot8=72\)

\(\Rightarrow3^x=\dfrac{72}{8}\)

\(\Rightarrow3^x=9\)

\(\Rightarrow3^x=3^2\)

\(\Rightarrow x=2\)

_____

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