Question 164790
3x^3 + 15x^2 - 12x^2 - 60x
(3x^3 + 15x^2) - (12x^2 + 60x)
Notice the sign change in the second group.
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Now, factor each group:
3x^2(x + 5) - 12x(x + 5)
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Now, factor out (x+5)
(x+5)[3x^2 - 12x]
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Now, factor terms inside the []:
(x+5)(3x)[x - 4]
Resulting in:
(3x)(x+5)(x-4)