SOLUTION: IF (x-5)(x^2-6x+4) = Ax^3 + Bx^2 + Cx + D, find the value of A+B+C+D

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Question 305364: IF (x-5)(x^2-6x+4) = Ax^3 + Bx^2 + Cx + D, find the value of A+B+C+D
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!


Since all we want is A%2BB%2BC%2BD we simply substitute x=1
and the right side will become that very sum:

%28x-5%29%28x%5E2-6x%2B4%29+=+Ax%5E3+%2B+Bx%5E2+%2B+Cx+%2B+D

%281-5%29%281%5E2-6%2A1%2B4%29+=+A%2A1%5E3+%2B+B%2A1%5E2+%2B+C%2A1+%2B+D

%28-4%29%28-1%29+=+A%2BB%2BC%2BD

4=A%2BB%2BC%2BD

The answer is 4

Edwin