# Thread: Irrasjonale likninger (don't know what it is in English)

1. Example:

x = √3x+7-1

x+1 = √3x+7

(x+1)Â² = (√3x+7)Â²

xÂ²+2x+1 = 3x+7

Question: Why +2x

xÂ²-6-x = 0

Question: Why -6-x?

x = -2 OR x = 3

Question: How can you see the answer will be -2 or 3?  2.

3. to expand the squared bracket like your example (x+1)^2 you square the x and then the number(1) then you multiply 1 by x by 2 (the power above the square) about your second question you move the l.h.s to the R.H.S with an opposite sign it will be x^2 +2x+1-3x-7=0 this is to be put in the form of the quadratic equation then you the equation becomes x^2-6x-1=0 this is to be able to find the roots of the quadrtic equation by the quadratic formula or by factorizing .I hope this helps .

Sara,  4. Now I understand why I couldn't figure it out. I'm taking math and had forgotten all about it, so I'm starting from scratch. It's been many years. Thanks for reply though.  Bookmarks
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