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3 tháng 7 2017

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

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

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

b, \(5x^3-5x^2y-10x^2+10xy\)

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

\(=\left(5x-10x\right)\left(x-y\right)=5x\left(x-2\right)\left(x-y\right)\)

c, \(2x^2-5x=x\left(2x-5\right)\)

f, \(3x^2-7x-10=3x^2+3x^2-10x-10\)

\(=3x^2\left(x+1\right)-10\left(x+1\right)=\left(3x^2-10\right)\left(x+1\right)\)

d, \(x^3-3x^2+1-3x=x^3-3x^2-3x+1\)

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

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

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

e, \(3x^2-6xy+3y^2-12z^2\)

\(=3\left(x^2-2xy+y^2-4z^2\right)\)

\(=3\left[\left(x-y\right)^2-4z^2\right]\)

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

g, \(x^4+1-2x^2=\left(x^2-1\right)^2\)

h, \(3x^2-3y^2-12x+12y=3\left(x^2-y^2\right)-12\left(x-y\right)\)

\(=3\left(x-y\right)\left(x+y\right)-12\left(x-y\right)\)

\(=\left(x-y\right)\left(3x+3y-12\right)\)

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

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

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

3 tháng 7 2017

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

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

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

b. \(5x^3-5x^2y-10x^2+10xy\)

\(=5\left[\left(x^3-x^2y\right)-\left(2x^2-2xy\right)\right]\)

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

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

c. \(2x^2-5x=x\left(2x-5\right)\)

d. \(x^3-3x^2+1-3x\)

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

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

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

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

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

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

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

e. \(3x^2-6xy+3y^2-12z^2\)

\(=3\left[x^2-2xy+y^2-4z^2\right]\)

\(=3\left[\left(x-y\right)^2-\left(2z\right)^2\right]\)

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

f. \(3x^2-7x-10\)

\(=3x^2-7x-7-3\)

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

\(=3\left(x^2-1\right)-7\left(x+1\right)\)

\(=3\left(x+1\right)\left(x-1\right)-7\left(x+1\right)\)

\(=\left(x+1\right)\left[3\left(x-1\right)-7\right]\)

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

g. \(x^4+1-2x^2=\left(x^2\right)^2-2.x^2+1=\left(x^2-1\right)^2\)

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

h. \(3x^2-3y^2-12x+12y\)

\(=3\left(x^2-y^2\right)-12\left(x-y\right)\)

\(=3\left(x-y\right)\left(x+y\right)-12\left(x-y\right)\)

\(=\left(x-y\right)\left[3\left(x+y\right)-12\right]\)

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

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

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

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

P/s: ( Có j sai ns nha nhiều số quá tui rối đầu )

28 tháng 6 2017

Phép trừ các phân thức đại số

14 tháng 2 2020

Bài 2: \(a,\frac{7x-1}{2x^2+6x}=\frac{7x-1}{2x\left(x+3\right)}=\frac{\left(7x-1\right)\left(x-3\right)}{2x\left(x+3\right)\left(x-3\right)}\) 

 \(\frac{5-3x}{x^2-9}=\frac{5-3x}{\left(x-3\right)\left(x+3\right)}=\frac{\left(5-3x\right)2x}{2x\left(x-3\right)\left(x+3\right)}\)

\(b,\frac{x+1}{x-x^2}=\frac{x+1}{x\left(1-x\right)}=-\frac{x+1}{x\left(x+1\right)}=-\frac{2\left(x-1\right)\left(x+1\right)}{2x\left(x-1\right)^2}\) 

 \(\frac{x+2}{2-4x+2x^2}=\frac{x+2}{2\left(x-1\right)^2}=\frac{2x\left(x+2\right)}{2x\left(x-1\right)^2}\)

\(c,\frac{4x^2-3x+5}{x^3-1}=\frac{4x^2-3x+5}{\left(x-1\right)\left(x^2+x+1\right)}\) 

\(\frac{2x}{x^2+x+1}=\frac{2x\left(x-1\right)}{\left(x-1\right)\left(x^2+x+1\right)}\)

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

\(d,\frac{7}{5x}=\frac{7.2\left(2y-x\right)\left(2y+x\right)}{2.5x\left(2y-x\right)\left(2y+x\right)}\)

\(\frac{4}{x-2y}=-\frac{4}{2y-x}=-\frac{4.2.5x\left(2x+x\right)}{2.5x\left(2y-x\right)\left(2y+x\right)}\)

\(\frac{x-y}{8y^2-2x^2}=\frac{x-y}{2\left(4y^2-x^2\right)}=\frac{x-y}{2\left(2y-x\right)\left(2y+x\right)}=\frac{5x\left(x-y\right)}{2.5x.\left(2y-x\right)\left(2y+x\right)}\)

17 tháng 5 2019

A= 3xy-11x2-5y.8xy-5+6

=(3-11-5.8-5+6).(x2.x2.x).(y.y.y)

=-47x5y3

5 tháng 12 2018

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

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

\(10\left(x-y\right)-6x\left(y-x\right)=10\left(x-y\right)+6x\left(x-y\right)=\left(10+6x\right)\left(x-y\right)=2\left(x-y\right)\left(3x+5\right)\)\(\left(x+1\right)^2-25=\left(x+1+5\right)\left(x+1-5\right)=\left(x+6\right)\left(x-4\right)\)

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

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

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

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

5 tháng 12 2018

thanks

28 tháng 6 2017

Rút gọn phân thức

Rút gọn phân thức

3 tháng 7 2018

đề bài kêu làm gì

11 tháng 7 2019

\(a,3x^3y^3-15x^2y^2=3x^2y^2\left(xy-5\right)\)

\(b,5x^3y^2-25x^2y^3+40xy^4\)

\(=5xy^2\left(x^2-5xy+8y^2\right)\)

\(c,-4x^3y^2+6x^2y^2-8x^4y^3\)

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

\(d,a^3x^2y-\frac{5}{2}a^3x^4+\frac{2}{3}a^4x^2y\)

\(=a^3x^2\left(y-\frac{5}{2}x^2+\frac{2}{3}ay\right)\)

\(e,a\left(x+1\right)-b\left(x+1\right)=\left(x+1\right)\left(a-b\right)\)

\(f,2x\left(x-5y\right)+8y\left(5y-x\right)\)

\(=2x\left(x-5y\right)-8y\left(x-5y\right)=\left(x-5y\right)\left(2x-8y\right)\)

\(g,a\left(x^2+1\right)+b\left(-1-x^2\right)-c\left(x^2+1\right)\)

\(=\left(x^2+1\right)\left(a-b-c\right)\)

\(h,9\left(x-y\right)^2-27\left(y-x\right)^3\)

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

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

11 tháng 7 2019

a,3x3y315x2y2=3x2y2(xy5)a,3x3y3−15x2y2=3x2y2(xy−5)

b,5x3y225x2y3+40xy4b,5x3y2−25x2y3+40xy4

=5xy2(x25xy+8y2)=5xy2(x2−5xy+8y2)

c,4x3y2+6x2y28x4y3c,−4x3y2+6x2y2−8x4y3

=2x2y2(2x3+4x2y)=−2x2y2(2x−3+4x2y)

d,a3x2y52a3x4+23a4x2yd,a3x2y−52a3x4+23a4x2y

=a3x2(y52x2+23ay)=a3x2(y−52x2+23ay)

e,a(x+1)b(x+1)=(x+1)(ab)e,a(x+1)−b(x+1)=(x+1)(a−b)

f,2x(x5y)+8y(5yx)f,2x(x−5y)+8y(5y−x)

=2x(x5y)8y(x5y)=(x5y)(2x8y)=2x(x−5y)−8y(x−5y)=(x−5y)(2x−8y)

g,a(x2+1)+b(1x2)c(x2+1)g,a(x2+1)+b(−1−x2)−c(x2+1)

=(x2+1)(abc)=(x2+1)(a−b−c)

h,9(xy)227(yx)3h,9(x−y)2−27(y−x)3

=9(xy)2+27(xy)3

27 tháng 8 2019

help me!!

27 tháng 3 2020
https://i.imgur.com/zwAtPMZ.jpg