SOLUTION: complete the square by finding the last term x^2-18x+_______

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Question 1069008: complete the square by finding the last term
x^2-18x+_______
Found 2 solutions by Alan3354, ikleyn:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
c = (b/2a)^2

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
The last term is 81:


x^2-18x + 81 = %28x-9%29%5E2.


Having the term "-18x", you can easily understand that it is "-2*9*x", hence, 9%5E2 = 81 is the last (third term) they are asking for.



MEMORIZE these identities:  x%5E2+%2B+2bx+%2B+b%5E2 = %28x%2Bb%29%5E2,

                            x%5E2+-+2bx+%2B+b%5E2 = %28x-b%29%5E2.