Answer:
Step-by-step explanation:
-3x^4 -9x^3+ 15x^2
-3x^2 ( x^2 + 3x -5)
if you use quadratic formula (see image)
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10x^3 -35x^2 +6x -21
5x2(2x-7) +3(2x-7)
(5 + 3) (2x-7)
