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Question

a) $x^7 + x^2 + 1$

b) $x^4 + 4x^4$

c) $32x^4 + 1$

d) $x^8+3x^4+1$

e) $( x + y )^5 - x^5 - y^5$

g) $( xy + 4 )^2 - ( 2x + 2y )^2$

h)$14x^2y - 21xy^2 + 28x^2 y^2$

Dark · Answer 1 · 8/3/2016 8:45:32 PM

$e,(x+y)^5-x^5-y^5=5x^4y+10x^3y^2+10x^2y^3+5xy^4=5xy(x^3+2x^2y+2xy^2+1)=5xy(x^3+x^2y+xy^2+x^2y+xy^2+y^3)=5xy(x+y)(x^2+xy+y^2)$

Sửa 03-08-16 08:45 PM

Dark
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Trả lời 03-08-16 08:22 PM

๖ۣۜTQT☾♋☽
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Lionel Messi · Answer 2 · 8/3/2016 8:54:10 PM

g) $(xy+4)^2-(2x+2y)^2$

$=(xy+4-2x-2y)(xy+4+2x+2y)$

$=(x-2)(y-2)(x+2)(y+2)$

Trả lời 03-08-16 08:54 PM

Lionel Messi
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Lionel Messi · Answer 3 · 8/3/2016 8:52:06 PM

h) $14x^2y-21xy^2+28x^2y^2=7xy(2x-3y+4xy)$

Trả lời 03-08-16 08:52 PM

Lionel Messi
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๖ۣۜTQT☾♋☽ · Answer 4 · 8/3/2016 8:14:32 PM

$a,x^7+2x^2+1=x^7-x^6+x^4-x^3+x^2+x^6-x^5+x^3-x^2+x+x^5-x^4+x^2-x+1=(x^5-x^4+x^2-x+1)(x^2+x+1)$

Trả lời 03-08-16 08:14 PM

๖ۣۜTQT☾♋☽
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