SOLUTION: Could you please help me to solve this: Using the quadratic formula solve: 2x^2 + 4x - 7 = 0 Thanks a lot

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Question 753459: Could you please help me to solve this:
Using the quadratic formula solve: 2x^2 + 4x - 7 = 0
Thanks a lot
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Have you covered completing the square?
That's how I would do it.
+2x%5E2+%2B+4x+-+7+=+0+
Divide both sides by +2+
+x%5E2+%2B+2x+-+7%2F2+=+0+
Add +7%2F2+ to both sides
+x%5E2+%2B+2x+=+7%2F2+
Take +1%2F2+ of the co-efficient of the
+x+ term, square it, then add it to
both sides
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+x%5E2+%2B+2x+%2B+%28+2%2F2+%29%5E2+=+7%2F2+%2B+%28+2%2F2+%29%5E2+
+x%5E2+%2B+2x+%2B+1+=+7%2F2+%2B+1+
+x%5E2+%2B+2x+%2B+1+=+9%2F2+
+%28+x+%2B+1+%29%5E2+=+9%2F2+
Take the square root of both sides
+x+%2B+1+=+3+%2F+sqrt%282%29+
+x+=+-1+%2B+3+%2F+sqrt%282%29+
and also
+x+%2B+1+=+-3+%2F+sqrt%282%29+
+x+=+-1+-+3+%2F+sqrt%282%29+
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These are the 2 answers. You can "clean them up"
by multiplying the 2nd term by +sqrt%282%29+%2F+sqrt%282%29+
That will give you:
+x+=+-1+%2B+3%2Asqrt%282%29+%2F+2+
+x+=+-1+-+3%2Asqrt%282%29+%2F+2+
-----------------------
Also, you can check both answers by plugging them
back into original equation.
Hope this helps