The sum of two number is 25 and their difference is 13. Find their product.

A.
104
B.
114
C.
315
D.
325

• x+y = 25
  x-y = 13
  solve it
  x = 19 and y = 6
  x*y = 19* 6 =114
• 12 years agoHelpfull: Yes(5) No(0)
• xy=((x+y)^2-(x+y)^2)/4
  =(625-169)/4
  =456/4
  =114
• 12 years agoHelpfull: Yes(1) No(0)
• Let the two numbers be x and y.
  given that
  x + y = 25 and x - y = 13
  we know that
  (x + y)^2 = x^2 + y^2 +2xy
  = x^2 + y^2 -2xy +2xy +2xy
  = (x - y)^2 + 4xy
  (25)^2 = (13)^2 + 4xy
  625 = 169 + 4xy
  4xy = 625 - 169
  4xy = 456
  xy = 114
  hence option B is the answer.
• 12 years agoHelpfull: Yes(1) No(0)
• let no be x & y
  given x+y = 25
  x-y = 13
  we have (x+y)^2 = (x-y)^2+ 4xy
  25*25-13*13=4xy
  xy = (625-169)/4
  = 114
• 12 years agoHelpfull: Yes(1) No(0)
• B. 114
  Explaination : Sum of two numbers is 25, X + Y = 25 ---------(1)
  Diff of 2 numbers is 13, X - Y = 13 ---------(2)
  By adding equation (1) & (2), we get
  2X = 38
  X = 19 (i.e, 38/2)
  By Substituting the value of X in eqn(1),
  19 + Y = 25
  Y = 25 - 19
  Y = 6
  So, the product of two numbers, X*Y = 19*6
  = 114
• 12 years agoHelpfull: Yes(0) No(0)
• x+y=25
  x-y=13
  x=13+y
  13+y++y=25
  2y=12
  y=6, x=19
  x*y=114
  
• 12 years agoHelpfull: Yes(0) No(0)
• x+y = 25
  x-y = 13
  x = 19 and y = 6
  x*y = 19* 6 =114
  
• 9 years agoHelpfull: Yes(0) No(0)
• x+y=25
  x-y=13
  2x =38
  x=19
  y=6
  x*y=19*6=114
• 9 years agoHelpfull: Yes(0) No(0)
• a+b=25
  a-b=13
  2a=38
  a=19
  b=6
  axb=114
• 9 years agoHelpfull: Yes(0) No(0)
• b. 114
  
  as 19+6=25 and 19-6=13
• 9 years agoHelpfull: Yes(0) No(0)
• a=6;b=19
  a+b=25
  a-b=13
  a*b=114
• 7 years agoHelpfull: Yes(0) No(0)