1. (40 * 40 * 40 – 31 * 31 * 31 ) / (40 * 40 *+ 40 – 31 + 31 * 31 ) = ? a) 8 b) 9 c) 71 d) 51

• a^3 - b^3 = (a-b)(a^2+ab+b^2)
  (40 * 40 * 40 – 31 * 31 * 31 ) / (40 * 40 *+ 40 – 31 + 31 * 31 )
  =(40-31)=9
  ans: b
• 12 years agoHelpfull: Yes(4) No(0)
• b)9
  
  By using a^3-b^3=(a-b)*(a^2+a*b+b^2), we solve this.
  Let a=40; b=31
  
  (40^3)-(31^3)=(40^2)+(40*31)+(31^2)
  (64000)-(29791)=(1600)+(1240)+(961)
  34209=3801
  x=34209/3801
  =9
  
• 12 years agoHelpfull: Yes(1) No(0)
• b)9
  
  By using a^3-b^3=(a-b)*(a^2+a*b+b^2), we solve this.
  Let a=40; b=31
  
  (40^3)-(31^3)=(40^2)+(40*31)+(31^2)
  (64000)-(29791)=(1600)+(1240)+(961)
  34209=3801
  x=34209/3801
  =9
  
• 12 years agoHelpfull: Yes(0) No(0)
• hello vijnesh hw u can use here a3+b3 formula
  
• 12 years agoHelpfull: Yes(0) No(0)