Step-by-step explanation:
x+2=0 x=-2
x^3+3x^2+5x+6
(-2)^3+3(-2)2+5(-2)+6
-8+12-10+6
0
hence x+2 is a factor of x^3+3x^2+5x+6
x+2=0
x=-2
2x+4
2(-2)+4
-4+4
also x+2 is a factor of 2x+4
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