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1978 AMC 12 Question 24

AMC12 · 1978 AMC 12

Question 24

If the distinct nonzero numbers $x(y-z),$ $y(z-x),$ $z(x-y)$ form a geometric progression with common ratio $r,$ then $r$ satisfies the equation
  1. $r^2+r+1=0$
  2. $r^2-r+1=0$
  3. $r^4+r^2-1=0$
  4. $(r+1)^4+r=0$
  5. $(r-1)^4+r=0$