Question

Phân tích đa thức thành nhân tử:

a,14x^2y-21xy^2=28x^2y^2

b,x(x+y)-5x-5y

c,10x(x-y)-8(y-x)

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

e,x^3+y^3+z^3-3xyz

g,5x^2-10xy+5y^2-20z^2                                                    

h,x^3-x+3x^2y+3xy^2+y^3-y

i,x^2+7x-8

k,x^2+4x+3

l,16x-5x^2-3

m,x^4+4

n,x^3-2x^2+x-xy^2                                                                         

Answer 1

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

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

c,\(10x\left(x-y\right)-8\left(y-x\right)=10x\left(x-y\right)+8\left(x-y\right)=\left(x-y\right)\left(10x-8\right)\)

d,\(\left(3x+1\right)^2-\left(x+1\right)^2=9x^2+6x+1-x^2-2x-1=7x^2-4x=x\left(7x-4\right)\)

e,\(x^3+y^3+z^3-3xyz=\)=a3+3ab(a+b)+b3+c3−3abc−3ab(a+b)
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