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2 tháng 7 2021

a) x2 + 5x + 6

= x2 + 2x + 3x + 6

= (x2 + 2x) + (3x + 6)

= x(x + 2) + 3 (x + 2)

= (x + 2) (x + 3)

b) x2 + 6x + 8

= x2 + 2x + 4x + 8

= (x2 + 2x) + (4x + 8)

= x(x + 2) + 4(x + 2)

= (x + 2)(x + 4)

c) x2 - 5x - 14

= x2 + 2x - 7x - 14

= (x2 + 2x) - (7x + 14)

= x(x + 2) - 7(x + 2)

= (x + 2)(x - 7)

d) x2 - 9x + 18

= x2 - 3x - 6x + 18

= (x2 - 3x) - (6x + 18)

= x(x - 3) - 6 (x - 3)

= (x - 3)(x - 6)

e) x- 7x + 12

= x2 -3x - 4x + 12

= (x2 - 3x) - (4x + 12)

= x(x - 3) - 4(x - 3)

= (x - 3)(x - 4)

f) 3x2 + 9x - 30

= 3(x2 + 3x - 10)

= 3\(\left[\left(x^2+5x-2x-10\right)\right]\)

= 3\(\left[\left(x^2+5x\right)-\left(2x-10\right)\right]\)

= 3\(\left[x\left(x+5\right)-2\left(x+5\right)\right]\)

= 3(x + 5)(x - 2)

 Chuc ban hoc tot

a) \(x^2+5x+6=\left(x+2\right)\left(x+3\right)\)

b) \(x^2+6x+8=\left(x+2\right)\left(x+4\right)\)

c) \(x^2-5x-14=\left(x-7\right)\left(x+2\right)\)

d) \(x^2-9x+18=\left(x-3\right)\left(x-6\right)\)

e) \(x^2-7x+12=\left(x-3\right)\left(x-4\right)\)

f) \(3x^2+9x-30=3\left(x^2+3x-10\right)=3\left(x+5\right)\left(x-2\right)\)

6 tháng 9 2020

a) \(x^2-5x+6=x^2-2x-3x+6=\left(x-2\right)\left(x-3\right)\)

b)\(3x^2+9x-30=3x^2-6x+15x-30=3\left(x-2\right)\left(x+5\right)\)

c)\(x^2-7x+12=x^2-3x-4x+12=\left(x-3\right)\left(x-4\right)\)

d)\(x^2-7x+10=x^2-2x-5x+10=\left(x-2\right)\left(x-5\right)\)

6 tháng 9 2020

a) \(x^2-5x+6=x^2-2x-3x+6=\left(x^2-2x\right)-\left(3x-6\right)\)

\(=x\left(x-2\right)-3\left(x-2\right)=\left(x-2\right)\left(x-3\right)\)

b) \(3x^2+9x-30=3\left(x^2+3x-10\right)=3\left(x^2-2x+5x-10\right)\)

\(=3\left[\left(x^2-2x\right)+\left(5x-10\right)\right]=3\left[x\left(x-2\right)+5\left(x-2\right)\right]\)

\(=3\left(x-2\right)\left(x+5\right)\)

c) \(x^2-7x+12=x^2-3x-4x+12=\left(x^2-3x\right)-\left(4x-12\right)\)

\(=x\left(x-3\right)-4\left(x-3\right)=\left(x-3\right)\left(x-4\right)\)

d) \(x^2-7x+10=x^2-2x-5x+10=\left(x^2-2x\right)-\left(5x-10\right)\)

\(=x\left(x-2\right)-5\left(x-2\right)=\left(x-2\right)\left(x-5\right)\)

18 tháng 10 2023

a) \(x^2-5x+6\)

\(=x^2-2x-3x+6=x\left(x-2\right)-3\left(x-2\right)=\left(x-2\right)\left(x-3\right)\)

b) \(x^2-9x+18=x^2-3x-6x+18\)

\(=x\left(x-3\right)-6\left(x-3\right)=\left(x-3\right)\left(x-6\right)\)

c) \(x^2-6x+5=x^2-x-5x+5\)

\(=x\left(x-1\right)-5\left(x-1\right)=\left(x-1\right)\left(x-5\right)\)

d) \(3x^2+5x-30=3\left(x^2+\dfrac{5x}{3}-10\right)=3\left(x^2+2.x.\dfrac{5}{6}+\dfrac{25}{36}-\dfrac{5347}{500}\right)\)

Câu này bạn xem lại đề nha

e) \(3x^2-5x-2=3x^2-6x+x-2\)

\(3x\left(x-2\right)+x-2=\left(x-2\right)\left(3x+1\right)\)

 

 

4 tháng 8 2020

Bài 1 : Phân tích các đa thức sau thành nhân tử : ( tách một hạn tử thành nhiều hạng tử )
a, 3x2 + 9x - 30

= 3(x2 + 3x - 10)

= 3(x2 + 5x - 2x - 10)

= 3[x(x + 5) - 2(x + 5)]

= 3(x + 5)(x - 2)

b, x2 - 3x + 2

= x2 - x - 2x + 2

= x(x - 1) - 2(x - 1)

= (x - 1)(x - 2)
c, x2 - 9x + 18

= x2 - 6x - 3x + 18

= x(x - 6) - 3(x - 6)

= (x - 6)(x - 3)
d, x2 - 6x + 8

= x2 - 4x - 2x + 8

= x(x - 4) - 2(x - 4)

= (x - 4)(x - 2)
e, x2 - 5x - 14

= x2 + 2x - 7x - 14

= x(x + 2) - 7(x + 2)

= (x + 2)(x - 7)
f, x2 + 6x + 5

= x2 + x + 5x + 5

= x(x + 1) + 5(x + 1)

= (x + 1)(x + 5)
h, x2 - 7x + 12

= x2 - 3x - 4x + 12

= x(x - 3) - 4(x - 3)

= (x - 3)(x - 4)
i, x2 - 7x + 10

= x2 - 2x - 5x + 10

= x(x - 2) - 5(x - 2)

= (x - 2)(x - 5)

#Học tốt!

24 tháng 10 2018

a) x2 - 5x + 6

= x2 - 2x - 3x + 6

=(x2 - 2x) - (3x + 6)

=x.(x - 2) - 3.(x - 2)

=(x-2).(x-3)

b) 3x2+9x-30

=3x2+15x-6x-30

=(3x2+15x) - (6x+30)

= 3x(x+5) - 6(x+5)

=(x+5).(3x-6)

c) x2-3x+2

=x2-2x-x+2

=(x2-2x) - (x-2)

=x(x-2)-(x-2)

=(x-2)(x-1)

24 tháng 10 2018

a)x- 5x + 6

= x- 2x - 3x + 6

=x.(x - 2) - 3(x - 2)

=(x - 2).(x - 3)

b)3x+9x -30

=3x+15x - 6x -30

=3x.(x+5) - 6.(x + 5)

=(x+5).(3x - 6)

c)x- 3x +2

=x- 2x - x +2

=x.(x- 2) - 1.(x-2)

=(x-2).(x - 1)

d)x- 9x +18

=x- 6x -3x +18

=x.(x - 6) -3.(x - 6)

=(x - 6).(x - 3)

e)x- 6x +8

=x- 2x - 4x +8

=x.(x - 2)- 4.(x - 2)

=(x - 2).(x - 4)

f)x- 5x -14

=x+ 2x - 7x - 14

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

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

21 tháng 10 2023

\(a,x^2-5x+6\\=x^2-3x-2x+6\\=x(x-3)-2(x-3)\\=(x-3)(x-2)\\---\\b,3x^2+9x-30\\=3x^2-6x+15x-30\\=3x(x-2)+15(x-2)\\=(x-2)(3x+15)\\=3(x-2)(x+5)\\---\)

\(c,x^2-3x+2\\=x^2-x-2x+2\\=x(x-1)-2(x-1)\\=(x-1)(x-2)\\---\\d,3x^2-5x-2\\=3x^2-6x+x-2\\=3x(x-2)+(x-2)\\=(x-2)(3x+1)\\Toru\)

13 tháng 5 2017

a)   \(x^2-3x+2\)

\(\Leftrightarrow x^2-2x-x+2\)

\(\Leftrightarrow x\left(x-2\right)-\left(x-2\right)\)

\(\Leftrightarrow\left(x-2\right)\left(x-1\right)\)

b)  \(x^2-6x+8\)

\(\Leftrightarrow x^2-4x-2x+8\)

\(\Leftrightarrow x\left(x-4\right)-2\left(x-4\right)\)

\(\Leftrightarrow\left(x-4\right)\left(x-2\right)\)

c)  \(3x^2+9x-30\)

\(\Leftrightarrow3\left(x^2+3x-10\right)\)

\(\Leftrightarrow3\left[\left(x^2+2\cdot\frac{3x}{2}+\frac{9}{4}\right)-\frac{49}{4}\right]\)

\(\Leftrightarrow3\left[\left(x+\frac{3}{2}\right)^2-\left(\frac{7}{2}\right)^2\right]\)

\(\Leftrightarrow3\left(x+\frac{3}{2}+\frac{7}{2}\right)\left(x+\frac{3}{2}-\frac{7}{2}\right)\)

\(\Leftrightarrow3\left(x-2\right)\left(x+5\right)\)

d)  \(x^2-9x+18\)

\(\Leftrightarrow x^2-3x-6x+18\)

\(\Leftrightarrow x\left(x-3\right)-6\left(x-3\right)\)

\(\Leftrightarrow\left(x-3\right)\left(x-6\right)\)

TK MK NKA !!!! TH@NK !!! 

3 tháng 8 2020

a) x2 - 3x + 2 ( như này mới phân tích được ạ :) )

= x2 - x - 2x + 2

= x( x - 1 ) - 2( x - 1 )

= ( x - 2 )( x - 1 )

b) x2 - 6x + 8

= x2 - 2x - 4x + 8

= x( x - 2 ) - 4( x - 2 )

= ( x - 4 )( x - 2 )

c) 3x2 + 9x - 30

= 3( x2 + 3x - 10 )

= 3( x2 - 2x + 5x - 10 )

= 3[ x( x - 2 ) + 5( x - 2 )]

= 3( x + 5 )( x - 2 )

d) x2 - 9x + 18

= x2 - 3x - 6x + 18

= x( x - 3 ) - 6( x - 3 )

= ( x - 6 )( x - 3 )

13 tháng 11 2019

1) \(x^2-6x+3\)

\(=x^2-6x+9-6\)

\(=\left(x-3\right)^2-6\)

\(=\left(x-3+\sqrt{6}\right)\left(x-3-\sqrt{6}\right)\)

2) \(2m^2+10m+8\)

\(=2m^2+2m+8m+8\)

\(=2m\left(m+1\right)+8\left(m+1\right)\)

\(=\left(2m+8\right)\left(m+1\right)\)

\(=2\left(m+4\right)\left(m+1\right)\)

3) \(9x^2+6x-8\)

\(=\left(9x^2+6x+1\right)-9\)

\(=\left(3x+1\right)^2-9\)

\(=\left(3x+4\right)\left(3x-2\right)\)

4) \(x^3-5x^2-14x\)

\(=x\left(x^2-5x-14\right)\)

\(=x\left(x^2-2x+7x-14\right)\)

\(=x\left[x\left(x-2\right)+7\left(x-2\right)\right]\)

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

13 tháng 11 2019

1) x^2-6x+3

= (x^2-6x+9)-6

=(x-3)^2-6

=(x-3-căn 6)(x-3+căn 6)

2) =2(m^2+5m+4)

=2(m+1)(m+4)

3) =9x^2+6x+1-9

=(3x+1)^-9

=(3x-2)(3x+4)

4, x^3-5x^2-14x

=x(x-7)(x+2)

5, a^4+4a^2-5

=a^4+4a^2+4-9

=(a^2+2)^-9

=(a^2-1)(a^2+5)

6, x^3-7x-6

=(x-3)(x+1)(x+2).

13 tháng 8 2020

a/\(x^2-5x+6=x^2-2x-3x+6=x\left(x-2\right)-3\left(x-2\right)=\left(x-2\right)\left(x-3\right)\)b/

\(3x^2+9x-30=3\left(x^2+3x-10\right)\)

c/

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

d/\(x^2-9x+18=x^2-3x-6x+18=x\left(x-3\right)-6\left(x-3\right)=\left(x-3\right)\left(x-6\right)\)e/

\(x^2-6x+8=x^2-2x-4x+8=x\left(x-2\right)-4\left(x-2\right)=\left(x-2\right)\left(x-4\right)\)f/\(x^2-5x-14=x^2+2x-7x-14=x\left(x+2\right)-7\left(x+2\right)=\left(x+2\right)\left(x-7\right)\)

g/

\(x^2-6x+5=x^2-x-5x+5=x\left(x-1\right)-5\left(x-1\right)=\left(x-1\right)\left(x-5\right)\)

h/

\(x^2-7x+12=x^2-4x-3x+12=x\left(x-4\right)-3\left(x-4\right)=\left(x-4\right)\left(x-3\right)\)i/\(x^2-7x+10=x^2-2x-5x+10=x\left(x-2\right)-5\left(x-2\right)=\left(x-2\right)\left(x-5\right)\)

a) Ta có: \(x^2-5x+6\)

\(=x^2-2x-3x+6\)

\(=x\left(x-2\right)-3\left(x-2\right)\)

\(=\left(x-2\right)\left(x-3\right)\)

b) Ta có: \(3x^2+9x-30\)

\(=3\left(x^2+3x-10\right)\)

\(=3\left(x^2+5x-2x-10\right)\)

\(=3\left[x\left(x+5\right)-2\left(x+5\right)\right]\)

\(=3\left(x+5\right)\left(x-2\right)\)

c) Ta có: \(x^2-3x+2\)

\(=x^2-x-2x+2\)

\(=x\left(x-1\right)-2\left(x-1\right)\)

\(=\left(x-1\right)\left(x-2\right)\)

d) Ta có: \(x^2-9x+18\)

\(=x^2-3x-6x+18\)

\(=x\left(x-3\right)-6\left(x-3\right)\)

\(=\left(x-3\right)\left(x-6\right)\)

e) Ta có: \(x^2-6x+8\)

\(=x^2-4x-2x+8\)

\(=x\left(x-4\right)-2\left(x-4\right)\)

\(=\left(x-4\right)\left(x-2\right)\)

f) Ta có: \(x^2-5x-14\)

\(=x^2-7x+2x-14\)

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

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

g) Ta có: \(x^2-6x+5\)

\(=x^2-x-5x+5\)

\(=x\left(x-1\right)-5\left(x-1\right)\)

\(=\left(x-1\right)\left(x-5\right)\)

h) Ta có: \(x^2-7x+12\)

\(=x^2-3x-4x+12\)

\(=x\left(x-3\right)-4\left(x-3\right)\)

\(=\left(x-3\right)\left(x-4\right)\)

i) Ta có: \(x^2-7x+10\)

\(=x^2-2x-5x+10\)

\(=x\left(x-2\right)-5\left(x-2\right)\)

\(=\left(x-2\right)\left(x-5\right)\)