Q. x^2-y^2= 16 and 2. xy=4 so find out x+y=? tell that both statement are required to find out the value of x+Y

• x^2-y^2= 16 = 25-9 =5^2-3^2
  => (x+y)*(x-y)=(5+3)*(5-3)
  => (x+y)=(5+3)=8
  only one statement required.
• 11 years agoHelpfull: Yes(35) No(6)
• @rakesh but if this is d soln then statement 2 is wrong...x*y=15 not 4
  ??
  
• 10 years agoHelpfull: Yes(10) No(1)
• both the statements are required
• 11 years agoHelpfull: Yes(4) No(6)
• X^2-y^2=16 then X^2-y^2=4^2 then x-y=4
  
  x^2-y^2=(x-y)(x+y)=16 then put the value of x-y=4 then x+y=4
• 11 years agoHelpfull: Yes(3) No(14)
• both required
• 11 years agoHelpfull: Yes(2) No(7)
• both required
• 11 years agoHelpfull: Yes(2) No(0)
• To solve this both the statements are required.
• 11 years agoHelpfull: Yes(1) No(0)
• Mr alok kumar you are absolutely write
  answer is statement 1 only
  
• 11 years agoHelpfull: Yes(1) No(2)
• Suppose x=5, y= -3
  
  in case of that x^2-y^2= 16 = 25-9 =5^2-(-3)^2
  => (x+y)*(x-y)=(5+(-3))*(5-(-3))
  => (x+y)=(5-3)=2
  
  So it can be either 8 or 2 .
  
  
• 9 years agoHelpfull: Yes(1) No(0)
• NO only 1 STATEMENT IS REQUIRED.
• 11 years agoHelpfull: Yes(0) No(1)
• ?? how both the statements r requied??
• 11 years agoHelpfull: Yes(0) No(0)
• if substitution is the method to ans for this ques.. then even 2nd statement is also satisfying by substituting either 4*1=4 or 2*2=4.. so ans will be..either 1 or 2.
• 10 years agoHelpfull: Yes(0) No(2)
• Only one statment is required. 2nd stmnt given for creating confusion..though we dont need
• 10 years agoHelpfull: Yes(0) No(1)
• only one statement is enough
  x^2-y^2=16
  (x-y)(x+y)=16
  by assumption x-y=4
  x+y=4
  by solving x=4,y=0
  therefore x+y=4
• 10 years agoHelpfull: Yes(0) No(0)
• (x-y)^2 = 0
  =>x^2-2xy+y^2=0
  => x^2-2xy+y^2+4xy-4xy=0 (add and substract 4xy)
  =>(x+y)^2-4xy=0
  =>(x+y)=underroot(4xy)
  =>(x+y)=4 (only xy=4 is require)
• 10 years agoHelpfull: Yes(0) No(1)