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If(x + 1) and (x + 2) are the factors x^3 +3x2-3ax + b then find a and b |
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Answer» x+1 and x+2 are factors so if we put x=-1 and -2 we will get 0 as an answer. x*x*x+3x*x-3ax+b f(-1)=(-1)(-1)(-1)+3(-1)(-1)-3a(-1)+b = 0 -1+3+3a+b = 0 3a+b = -2 f(-2)=(-2)(-2)(-2)+3(-2)(-2)-3a(-2)+b = 0 -8+12+6a+b = 0 6a+b = -4 6a+b-3a-b = -4-(-2) 3a = -2 a = -2/3 3(-2/3)+b = -2 -2+b = -2 b = 0 |
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