`a)20x^3y^4-5x^2y^3+100x^2y^4`
`=5x^2y^3(4xy-1+20y)`
`b)x^2-xy-15x+15y`
`=x(x-y)-15(x-y)`
`=(x-15)(x-y)`
`c)2x^3+8x^2+8x`
`=2x(x^2-4x+4)`
`=2x(x-2)^2`
`d)x^3-27y^6`
`=x^3-(3y^2)^3`
`=(x-3y)(x^2+3xy^2+9y^4)`
`e)36x^2-a^2+10a-25`
`=36x^2-(a^2-10a+25)`
`=(6x)^2-(a-5)^2`
`=(6x-a+5)(6x+a-5)`
A,20x^3y^4 -5x^2y^3 +100x^2y^4
=20x^2xy^3y - 5x^2y^3 + 100x^2y^3y
=4*5x^2xy^3y - 5x^2y^3 + 4 * 5 *5x^2y^3y
=5x^2y^3(4xy-1+20y)
b)B,x^2-xy-15x+15y
=(x^2-xy)-(15x+15y)
=x(x-y)-15(x-y)
=(x-15)*(x+y)
c)C,2x^3+8x^2+8x
=2x(x^2-4x-4)
=2x(x-2)^2
D,x^3-27y^6
=x^3-(3y^2)^3
=(x-3y^2)*(x^2+x*3y^2+(3y^2)^2)
=(x-3y^2) *(x^2+3xy^2+9y^4)
E,36x^2-a^2+10a-25
=36x^2 - (a-5)^2
=(6x)^2 - (a-5)^2
=(6x-a+5) * (6x+a-5)
cho mik 5* dc khum
