SOLUTION: Solve by completing the square: x^2 + 8x-3 = 0

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Question 34171: Solve by completing the square: x^2 + 8x-3 = 0

Answer by Cintchr(481) About Me  (Show Source):
You can put this solution on YOUR website!
+x%5E2+%2B+8x-3+=+0+
To complete the square, you must make the left side a perfect square trinomial.
Add three to both sides
+x%5E2+%2B+8x+=+3+
using +%28b%2F2%29%5E2+ find the number that will "complete the square"
+%288%2F2%29%5E2+=+4%5E2+=+16+
Add 16 to both sides
+x%5E2+%2B+8x+%2B+16+=+3+%2B+16+
Factor the left ... add the right
+%28x%2B4%29%5E2+=+19+
Squareroot both sides
+x%2B4+=+sqrt%2819%29+
subtract 4 from both sides
+x+=+-4+%2B-+sqrt%2819%29+
Remember that there is a + and a - since there has to be two solutions for a perfect square trinomial