find the smallest number in GP whose sum is 38 and product is 1728

• Let x,y,z be the numbers in geometric progression?
  y^2=xz
  x+y+z=38
  xyz=1728
  xyz = xzy = y^2y = y^3 = 1728
  y = 12
  y^2=xz=144
  z=144/x
  x+y+z = x+12+144/x = 38
  x^2+12x+144=38x
  x^2-26x+144=0
  (x-18)(x-8)=0
  x=8,18
  If x =8, z = 38-8-12=18
  The numbers are 8,12, 18
  
  Their sum is 38
  Their product is 1,728
  
  The smallest number is 8
• 13 years agoHelpfull: Yes(17) No(0)
• 38r^2+1728r+1728=0
  
  solve for r?
• 13 years agoHelpfull: Yes(0) No(7)