SOLUTION: Solve the equation by completing the square: p^2+3p-9=0

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Question 269463: Solve the equation by completing the square:
p^2+3p-9=0
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
To complete the square rewrite the equation as
(i) p%5E2+%2B+3p+%2B+_____+=+9+%2B+______
step 1 - take 1/2 of the middle term and square it to get
(ii) p%5E2+%2B+3p+%2B+%283%2F2%29%5E2+=+9+%2B+%283%2F2%29%5E2
notice the blanks were used to put the 1/2 term squared.
step 2 - rewrite the left side as a binomial squared and simplify the right side to get
(iii) %28p+%2B+3%2F2%29%5E2+=+45%2F4
step 3 - take a square root to get
(iv) p+%2B+3%2F2+=+%2B-sqrt%2845%29%2F2
step 4 - subtract 3/2 to get
(v) p+=+%28-3+%2B-sqrt%2845%29%29%2F2