How would I factorize x^3+2x^2-9x-18 and then solve f(x)=0? Thanks a lot.
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Originally Posted by Yppolitia How would I factorize x^3+2x^2-9x-18 and then solve f(x)=0? Thanks a lot. Factor by grouping: (Typically if you are asked to factor a cubic it will be a variation of this method.) Now note that factors: So we get: So if we have Then So x = -3, -2, or 3. -Dan
also if you do not know how to factor that well you could try and find one root, with the rational root theorem. lets say that u have now since this has a root lets call it we then have where . as you notice the degree of Q is one less than that of f.
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