\(x^3-9x^2+27x-27\)

=\(x^3-3.x^2.3+3.x.3^3-3^3\)

\(\left(x-3\right)^3\)

Thay x=1, ta có:

(1-3)³=-2³=-8

em đăng gộp bài vào nhé, mỗi bài tầm 3 -> 5 câu trả lời 1 lượt cho nhanh :>

sửa đề 1, \(A=x^3-9x^2+27x-27=\left(x-3\right)^3\)

Thay x = 103 vào A ta được : \(\left(103-3\right)^3=1000000\)

bài 60; tính giá trị biểu thức

1, A = x mũ 3 - 9x mũ 2 + 27 - 27 tại x = 103

= x^3 -9x^2 + 27 -27 ; (x = 103)

= 997246

Trả lời:

\(A=x^3-9x^2+27x-27=\left(x-3\right)^3\)

Thay x = 103 vào B, ta có:

\(A=\left(103-3\right)^3=100^3=1000000\)

A = 2015 . ( 27 - 3 ) - 27 . ( 2015 - 3 ) + 2015  x 3

A = 2015 x  27 - 2015 x 3 - 27 x 2015 + 27 x 3 + 2015 x 3

A = 2015 x 27 - 27 x 2015 - 2015 x 3 + 2015 x 3 + 27 x 3

A = 0 - 0 + 27 x 3

A = 81

Ủng hộ nhé ! 

A = 2015 ( 27 - 3 ) - 27 ( 2015 - 3 ) + 2015 x 3

A = 2015 x 27 - 2015 x 3 - 27 x 2015 + 27 x 3 + 2015 x 3

A = 2015 x 27 - 27 x 2015 - 2015 x 3 + 2015 x 3 + 27 x 3

A = 0 - 0 + 27 x 3

A = 81

A=2015.(27-3)-27.(2015-3)+2015*3

A=2015*27-2015.3-27.2015+27.3+2015.3

A=2015.27-27.2015-2015.3+2015.3+27.3

A=0-0+27.3

A=0+27.3

A=0+81

A=81

\(x^3-9x^2+27x-27=x^3-3.x^2.3+3.x.3^2-3^3=\left(x-3\right)^3\)

Thay x=5,ta có: \(\left(x-3\right)^3=\left(5-3\right)^2=2^3=8\)

Vậy...............

a) 584 - 123 x 3

= 584 - 369

= 215                             

b) 276 + 27 x 3 

= 276 + 81

= 357

\(a,584-123\times3\\ =584-369\\ =215\\ \\ b,276+27\times3\\ =276+81\\ =357\)

a , 584 - 123 x 3                                       b, 276 + 27 x 3 

= 584 - 369                                               

=      215

a) M = ( x   –   1 ) 3  với x = 1001 thì M = 109.

b) N = ( x   +   y   –   3 ) 3  với x = 2; y = 6 thì N = 125.

c) P = ( 3 xz ²   –   2 y ) 3  với x = 25; y = 150; z = 2 thì P = 0.

\(a,=\left(2x-7\right)^2=\left(2.4-7\right)^2=1\)

\(b,\left(x-3\right)^3=\left(5-3\right)^3=8\)

a)   \(4x^2-28x+49\)

\(=\left(2x-7\right)^2\)

\(=\left(2.4-7\right)^2=1\)

b)  \(x^3-9x^2+27x-27\)

\(=\left(x-3\right)^3\)

\(=\left(5-3\right)^3=8\)

a) 125 : m = 125 : 5  = 25

b) (b + 4) x 3 = (27 + 4) x 3   = 31 x 3  = 93

Zzz 🐇

a)125 : m = 125 : 5 = 2

 b)(b + 4) x 3 = (27 + 4) x 3 = 31 x 3 = 93

a: Khi m=5 thì \(125:m=125:5=25\)

b: Khi b=27 thì \(\left(b+4\right)\cdot3=\left(27+4\right)\cdot3=31\cdot3=93\)

2, 

a) \(315-\left(135-x\right)=215\)

\(\Rightarrow135-x=315-215\)

\(\Rightarrow135-x=100\)

\(\Rightarrow x=135-100\)

\(\Rightarrow x=35\)

b) \(x-320:32=25\cdot16\)

\(\Rightarrow x-10=5^2\cdot4^2\)

\(\Rightarrow x-10=20^2\)

\(\Rightarrow x-10=400\)

\(\Rightarrow x=410\)

c) \(3\cdot x-2018:2=23\)

\(=3\cdot x-1009=23\)

\(\Rightarrow3\cdot x=1032\)

\(\Rightarrow x=1032:3\)

\(\Rightarrow x=344\)

d) \(280-9\cdot x-x=80\)

\(\Rightarrow280-x\cdot\left(9+1\right)=80\)

\(\Rightarrow280-10\cdot x=80\)

\(\Rightarrow10\cdot x=280-80\)

\(\Rightarrow10\cdot x=200\)

\(\Rightarrow x=20\)

e) \(38\cdot x-12\cdot x-x\cdot16=40\)

\(\Rightarrow x\cdot\left(38-12-16\right)=40\)

\(\Rightarrow x\cdot10=40\)

\(\Rightarrow x=40:10\)

\(\Rightarrow x=4\)

bài 1 cậu ko giải giúp mình dc à