9,4,16,6,36,21,441

• 9-5=4
  4*4=16
  16-10=6
  6*6=36
  36-15=21
  21*21=441
  hence 441-20=421
• 11 years agoHelpfull: Yes(81) No(3)
• 9-4=5
  16-6=10
  36-21=15
  so it added 5 every time in differences
  so 15+5=20
  so 441-20=421
  
• 11 years agoHelpfull: Yes(19) No(2)
• 9-5=4
  4*4=16
  16-10=6
  6*6=36
  36-15=21
  21*21=441
  hence 441-20=421
• 10 years agoHelpfull: Yes(3) No(0)
• "-5,square,-10,square,..." (9-5=4; 4^2=16 agn 16-10=6 ; 6^2=36 , 36-15=21; 21^2=441,) ans: 441-20="421"
• 11 years agoHelpfull: Yes(2) No(0)
• 3 because it is square before of every number.
• 11 years agoHelpfull: Yes(1) No(7)
• 3*3=9-5=4*4=16-10=6*6=36-15=21*21=441-20=421
  
• 11 years agoHelpfull: Yes(1) No(0)
• answer is 421
• 9 years agoHelpfull: Yes(0) No(0)
• 9-4=5
  16-6=10
  36-21=15
  441-x=20 therefor 421
  
• 8 years agoHelpfull: Yes(0) No(0)
• 9-4=5
  16-6=10
  36-21=15
  so in next term we will have 20 as a difference.
  so 441-20 = 421
  
• 7 years agoHelpfull: Yes(0) No(0)