Problem: Find all real values of x for which x+x−21+x+2+x1=41
Solution
Solution: We note that 41=x+x−21+x+2+x1=(x+x−2)(x−x−2)x−x−2+(x+2+x)(x+2−x)x+2−x=2x−x−2+2x+2−x=21(x+2−x−2), so that 2x+2−2x−2=1 Squaring, we get that 8x−8(x+2)(x−2)=1⇒8x−1=8(x+2)(x−2). Squaring again gives 64x2−16x+1=64x2−256 so we get that x=16257.
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