1) If we subtract a number with y, we get 4 increase of number, once it got divided by y itself... Find that number??

• y-n=n+4,y=2n+4,then we get=n/2n+4
• 12 years agoHelpfull: Yes(5) No(42)
• Reduce the equation to General form ax2+bx+c=0:
  Taking the unknown number as 'n',
  
  n-y=4+(n/y)
  
  y2+(4-n)y+n=0
  
  We know the solution for this which is: x1 = -b+sqrt(b2-4ac)]/2a and
  x2 = -b-sqrt(b2-4ac)]/2a
  
  So the term inside the square root should be a perfect square.
  (Otherwise we get answer for y as fraction)
  In this case:
  
  sqrt(b2-4ac)= sqrt[(4-n)^2-4n]
  
  Now you got the General eq:Check all the answers now,
  This will be easier because you don't have to derive the equation for all the four options, so you time is saved.
  
  For 12 we get sqrt(16)=4.
  Which is not fraction.
  
• 11 years agoHelpfull: Yes(3) No(7)
• x-y=4+(x/y)
  we need to work with the options here.
  subs 12 first
  12-y=4+(12/y)
  solving this eq, we get y=6
  this satisfies the given condition
• 9 years agoHelpfull: Yes(2) No(1)