Question

if x-1 and x+2 are factors of x3+10x2+ax+b the find the values of a and b

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Answer 1

Answer:

(x-1)(x+2)=x^2+x-2

divide x^3+10x^2+ax+b by x^2+x-2

reminder=x(a-11)+b-18 should be 0

For this to be zero, a=18 and b=18