The product of two numbers is 120 and the sum of their squares is 289. The sum of the number is:

A)20
B)23
C)169
D)None of these

• let the no.s be a and b
  given,
  a*b=ab=120
  a2+b2=289
  now (a+b)2=a2+b2+2ab
  putting values,we get
  a+b=sqrt(289+2*120)
  =sqrt(289+240)
  =sqrt(529)
  =23
  
  
• 12 years agoHelpfull: Yes(11) No(0)
• a^2+b^2=289,a*b=120
  a^2+b^2+2ab=529
  a^2+b^2-2ab=49
  a+b=23
  a-b=7
  a=15
  b=8
  
• 12 years agoHelpfull: Yes(5) No(0)
• let x,y ne two nums..given xy=120 x^2+y^2=289
  we know that (x+y)^2=x^2+y^2+2xy (x+y)^2=289+2(120)=529..implies x+y=23
• 12 years agoHelpfull: Yes(1) No(0)
• let the numbers be x&y
  xy=120
  x^2 + y^2=289
  (x+y)^2 - 2xy=289
  (x+y)^2= 289-2xy
  = 289-2*120
  =289-240
  (x+y)^2= 49
  x+y=7
• 9 years agoHelpfull: Yes(1) No(0)
• 23
  by using (a+b)^2=a^2+b^2+2*ab
  here ab is 120, and a^2+b^2 is 289
  (a+b)^2=289+2*102=529
  a+b=23
  
• 9 years agoHelpfull: Yes(0) No(0)
• lets a*b=120 and
  a^2 + b^2=289
  ==> (a+b)^2 - 2*a*b=289
  (a+b)^2 = 529
  (a+b) = 23
  So, answe is B. 23
• 9 years agoHelpfull: Yes(0) No(0)
• 15*8=120,15^2+8^2=289,so nos are 15,8 nd sum =23..
• 9 years agoHelpfull: Yes(0) No(0)
• 8*15=120
  8^2+15^2 =289
  8+15=23
• 7 years agoHelpfull: Yes(0) No(0)
• x^2 + y^2 =(x+y)^2 - 2xy
  289=(x+y)^2 - 2*120
  x+y=23
• 7 years agoHelpfull: Yes(0) No(0)