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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

Phép trừ các phân thức đại số

27 tháng 8 2019

help me!!

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

30 tháng 10 2018

Bài 1:

a, \(6x^2\left(3x^2-4x+5\right)=18x^4-24x^3+30x^2\)

b, \(\left(3x-y\right)^2=9x^2-6xy+y^2\)

c, \(\left(x+3\right)\left(x-3\right)-x\left(x-5\right)=x^2-9-x^2+5=-4\)

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

\(=x^2+4x+4+x^2-6xy+9y^2-2x^2+2x+12\)

\(=9y^2+6x+16\)

30 tháng 10 2018

Bài 2:

a, \(14x^2y-21xy^2+28x^2y^2=7xy\left(2x-3y+4xy\right)\)

b, \(27x^3-\dfrac{1}{27}=\left(3x\right)^3-\left(\dfrac{1}{3}\right)^3=\left(3x-\dfrac{1}{3}\right)\left(9x^2-x+\dfrac{1}{9}\right)\)

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

d, \(x^2+7x+12=x^2+3x+4x+12=x\left(x+3\right)+4\left(x+3\right)=\left(x+3\right)\left(x+4\right)\)

a: \(=3y^2-5x^2y^3-2y^2+3x^2y^3=y^2-2x^2y^3\)

b: \(=6x-y+2x^2+3y^2-2x^2+x=7x-y+3y^2\)

c: \(=x-y+4y^2-6xy+\dfrac{10x^2}{y}\)

 

23 tháng 9 2018

\(a.\left(9x^2y^3-15x^4y^4\right):3x^2y-\left(2-3x^2y\right)y^2\)

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

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

\(b.\left(6x^2-xy\right):x+\left(2x^3y+3xy^2\right):xy-\left(2x-1\right)x\)

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

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

\(c.\left(x^2-xy\right):x+\left(6x^2y^5-9x^3y^4+15x^4y^3\right):\dfrac{3}{2}x^2y^3\)

\(=x-y+4y^2-6xy+10x^2\)

23 tháng 9 2018

Oa, giờ mới biết bác cũng ở box Toán :))

12 tháng 7 2017

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

\(=3x^2-6x-5x+5x^2-8x^2+24\)

\(=24-11x\)

b) \(\left(4x^2-3y\right)\cdot2y-\left(3x^2-4y\right)\cdot3y\)

\(=8x^2y-6y^2-9x^2y+12y^2\)

\(=6y^2-x^2y\)

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

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

\(=6xy^2-3y^2+3y^3+3y^2-y+y^2+y^3+y\)

\(=4y^3+y^2+6xy^2\)