Simultaneous Equations

• Callie ng88

  25 Apr 09, 12:21

  Please help to solve this equation with workings:

  square root of  -2x   +  square root of  y  =  5

  square root of  -2x   -   square root of  y  =   -1

  3x   +  y   =  3

  Thanks.

• tinuviel07

  25 Apr 09, 12:26

  Originally posted by Callie ng88:

  Please help to solve this equation with workings:

  square root of  -2x   +  square root of  y  =  5

  square root of  -2x   -   square root of  y  =   -1

  3x   +  y   =  3

  Thanks.

  y =12?

• dkcx

  25 Apr 09, 12:29

  When did simulataneous equations start requiring 3 equations? Can't it be done but just changing the 3rd equation to y = 3-3x and sub it into either of the above 2 equations?

  Having square root of -2x means x has to be a negative value liao since u don't square root negative numbers.

• skythewood

  25 Apr 09, 12:30

  Bring "square root of  -2x" to one side. bring the other stuff to the other side.

  Square both side. get equation. do this first.

• crimson soldier

  25 Apr 09, 13:41

  this isn't too hard, I encourage you to solve it yourself. Answer: y=9, x= -2 

  I too am wondering why you have 3 equations for 2 variables