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15 votes
15 votes
Factor completely 21b^4 +5b^2m^2- 4m^2

User Delphidabbler
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1 Answer

21 votes
21 votes

Factor completely


21b^4+5b^2m^2-4m^4

We need to split the expression into convenient groups


21b^4+5b^2m^2-4m^4=21b^4+12b^2m^2-4m^4-7b^2m^2

Factor 3b^2 from the first group and -m^2 from the second group:


21b^4+5b^2m^2-4m^4=3b^2(7b^2+4m^2)-m^2(4m^2+7b^2)

Factor out the common term 7b^2+4m^2:


21b^4+5b^2m^2-4m^4=(3b^2-m^2)(4m^2+7b^2)

This is the final factorization

User Anton Holmberg
by
3.3k points
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