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# How would you complete the square of these two expressions? Watch

1. Can someone please walk me through and explain the process of completing the square of these expressions:

1) x^2 + 4x -5

2) x^2 - 20x +10

Thanks!
2. (Original post by blobbybill)
Can someone please walk me through and explain the process of completing the square of these expressions:

1) x^2 + 4x -5

2) x^2 - 20x +10

Thanks!
Do you know where to begin? Have you tried anything?
3. (Original post by RDKGames)
Do you know where to begin? Have you tried anything?
I know you halve the co-efficient of X and put it in a bracket, then square the bracket, but I don't know how that would work if one of the signs was negative and another was positive (eg the first question)
4. (Original post by blobbybill)
I know you halve the co-efficient of X and put it in a bracket, then square the bracket, but I don't know how that would work if one of the signs was negative and another was positive (eg the first question)
In exactly the same way. Remember that so subtracting a number is the same as adding the negative of it.

So the first one would be just as you said:

Can you work out and as a result work out the completed square form from there?

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Updated: September 14, 2016
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