(x+1) and (x+2) are factor of x^3+3x^2-3ax+b find a. and b
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x+1=0
x=-1
Substituting in equation
(-1)³+3(-1)²-3a(-1)+b=0
-1+3+3a+b=0
3a+b=-2
x+2=0
x=-2
Substituting in equation
(-2)³+3(-2)²-3a(-2)+b=0
-8+12+6a+b=0
6a+b=-4
3a+b=-2
3a=-2
a=-2/3
-2+b=-2
b=0
x=-1
Substituting in equation
(-1)³+3(-1)²-3a(-1)+b=0
-1+3+3a+b=0
3a+b=-2
x+2=0
x=-2
Substituting in equation
(-2)³+3(-2)²-3a(-2)+b=0
-8+12+6a+b=0
6a+b=-4
3a+b=-2
3a=-2
a=-2/3
-2+b=-2
b=0
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