\(x^2-6x+8\)

b) \(x^2-4x...">

K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

5 tháng 8 2018

\(x^2-6x+8\)

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

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

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

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

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

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

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

\(x^2-x-12\)

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

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

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

5 tháng 8 2018

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

b) \(x^2-4x+3=x^2-x-3x+3=x\left(x-1\right)-3\left(x-1\right)\\ =\left(x-1\right)\left(x-3\right)\)

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

5 tháng 8 2018

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

b) \(x^2-4x+3=x^2-x-3x+3=x\left(x-1\right)-3\left(x-1\right)=\left(x-1\right)\left(x-3\right)\)

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

5 tháng 8 2018

a) x^2 -6x +8 

= x^2 - 2x -4x +8

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

= (x-2)(x-4)

b) x^2 - 4x +3

= x^2 -x - 3x +3

= x(x-1) -3(x-1)

= (x-1)(x-3)

10 tháng 10 2018

a) \(x^2-6x+8\)

\(=x^2-2\cdot x\cdot3+3^2-1\)

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

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

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

Còn lại tương tự

a) \(x^2-6x+8=x^2-2x-4x+8\)                     

\(=\left(x^2-2x\right)-\left(4x-8\right)\)

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

22 tháng 9 2019

a) \(x^2+7x+12\)

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

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

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

b) \(x^2+6x+8\)

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

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

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

c) \(x^2-10x+16\)

\(=\left(x^2-2x\right)-\left(8x-16\right)\)

\(=x\left(x-2\right)-8\left(x-2\right)\)

\(=\left(x-2\right)\left(x-8\right)\)

d) \(x^2-8x+15\)

\(=\left(x^2-3x\right)-\left(5x-15\right)\)

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

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

e) \(x^2-8x-9\)

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

\(=x\left(x+1\right)-9\left(x+1\right)\)

\(=\left(x+1\right)\left(x-9\right)\)

f) \(x^2+14x+48\)

\(=\left(x^2+6x\right)+\left(8x+48\right)\)

\(=x\left(x+6\right)+8\left(x+6\right)\)

\(=\left(x+6\right)\left(x+8\right)\)

24 tháng 7 2016

a)\(2x^2+x-6=2x^2+4x-3x-6=\left(x+2\right)\left(2x-3\right)\)

b)\(6x^4+7x^2+2=6x^4+4x^2+3x^2+2=\left(3x^2+2\right)\left(2x^2+1\right)\)

c)\(2x^2-3x-2700=2x^2+72x-75x+2700=\left(2x-75\right)\left(x+36\right)\)

2 tháng 7 2018

a)  \(x^2+3x+2\)

\(=\left(x^2+2x\right)+\left(x+2\right)\)

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

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

b)  \(x^2+5x+6\)

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

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

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

c)  \(x^2+5x+6\)

( giống câu b -_- )

d)  \(x^2+7x+12\)

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

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

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

2 tháng 7 2018

\(1,x^2+3x+2\)

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

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

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

\(2,x^2+5x+6\)

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

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

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

\(4,x^2+7x+12\)

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

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

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

\(5,x^2-4x+3\)

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

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

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

\(6,x^2+3x-4\)

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

\(=x\left(x-1\right)+4\left(x-1\right)\)

\(=\left(x+4\right)\left(x-1\right)\)

\(8,x^2-3x-10\)

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

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

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

29 tháng 8 2018

mk viết đáp án, ko biết biến đổi ib mk

a)  \(x^3+3x^2y-9xy^2+5y^3=\left(x+5y\right)\left(x-y\right)^2\)

b)    \(x^4+x^3+6x^2+5x+5=\left(x^2+5\right)\left(x^2+x+1\right)\)

c)   \(x^4-2x^3-12x^2+12x+36=\left(x^2-6\right)\left(x^2-2x-6\right)\)

d)   \(x^8y^8+x^4y^4+1=\left(x^2y^2-xy+1\right)\left(x^2y^2+xy+1\right)\left(x^4y^4-x^2y^2+1\right)\)

28 tháng 6 2017

Phép nhân các phân thức đại số

8 tháng 7 2016

b, \(\left(x^2+x\right)^2+4x^2+4x-12=x^4+2x^3+x^2+4x^2+4x-12\)

                                                         \(=x^4+2x^3+5x^2+4x-12\)

                                                         \(=\left(x^4-x^3\right)+\left(3x^3-3x^2\right)+\left(8x^2-8x\right)+\left(12x-12\right)\)

                                                         \(=x^3\left(x-1\right)+3x^2\left(x-1\right)+8x\left(x-1\right)+12\left(x-1\right)\)

                                                          \(=\left(x^3+3x^2+8x+12\right)\left(x-1\right)\)

                                                          \(=\left[\left(x^3+2x^2\right)+\left(x^2+2x\right)+\left(6x+12\right)\right]\left(x-1\right)\)

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

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

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

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

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

9 tháng 7 2016

a)\(x^5+x^4+1=x^5-\left(-x^3+x^3\right)+x^4+\left(x^2-x^2\right)+\left(x-x\right)+1\)

\(=x^5-x^3+x^2+x^4-x^2+x+x^3-x+1\)

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

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

b,c có ng lm rồi

d)\(2x^4-3x^3-7x^2+6x+8\)

Ta thấy x=-1 là nghiệm của đa thức 

=>đa thức có 1 hạng tử là x+1

\(\Rightarrow\left(x+1\right)\left(2x^3-5x^2-2x+8\right)\)

\(\Rightarrow\left(x+1\right)\left[2x^3-x^2-4x-4x^2+2x+8\right]\)

\(\Rightarrow\left(x+1\right)\left[x\left(2x^2-x-4\right)-2\left(2x^2-x-4\right)\right]\)

\(\Rightarrow\left(x+1\right)\left(x-2\right)\left(2x^2-x-4\right)\)

phần còn lại bạn tự lo nhé

13 tháng 10 2019

\(e,-5x+x^2-14\)

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

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

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

\(f,x^3+8+6x\left(x+2\right)\)

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

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

\(g,15x^2-7xy-2y^2\)

\(=15x^2+3xy-10xy-2y^2\)

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

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

\(h,3x^2-16x+5\)

\(=3x^2-x-15x+5\)

\(=x\left(3x-1\right)+5\left(3x-1\right)\)

\(=\left(3x-1\right)\left(x+5\right)\)

13 tháng 10 2019

\(a,x^3+2x^2y+xy^2=x\left(x^2+2xy+y^2\right)\)

\(=x\left(x+y\right)^2\)

\(b,4x^2-9y^2+4x-6y\)

\(=4x^2+4x+1-\left(9y^2+6y+1\right)\)

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

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

\(c,-x^2+5x+2xy-5y-y^2\)

\(=-\left(x^2-2xy+y^2\right)+5\left(x-y\right)\)

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

\(=\left(x-y\right)\left(y-x+5\right)\)

\(d,x^2+4x-12\)

\(=x^2-2x+6x-12\)

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

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