How do you factor $m^{3} - 7 m^{2} - 4 m + 28$ $m^3 - 7m^2 - 4m + 28$ ?

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Answer 1 · 2015-05-23T15:22:01

Grouping will work - notice the common ratio between the coefficients of the 1st and 2nd term and between the coefficients of the 3rd and 4th term...

$m^{3} - 7 m^{2} - 4 m + 28 = (m^{3} - 7 m^{2}) - (4 m - 28)$ $m^3-7m^2-4m+28 = (m^3-7m^2)-(4m-28)$

$= m^{2} (m - 7) - 4 (m - 7)$ $=m^2(m-7)-4(m-7)$

$= (m^{2} - 4) (m - 7)$ $=(m^2-4)(m-7)$

$= (m - 2) (m + 2) (m - 7)$ $=(m-2)(m+2)(m-7)$

How do you factor m^3 - 7m^2 - 4m + 28m3−7m2−4m+28 m^3 - 7m^2 - 4m + 28?