How do you know whether to add or subtract in simultaneous equations?

  • -1 votes

PLease Help!!

I don't really understand simultaneous equations

Posted Fri 3rd June, 2011 @ 14:09 by Naomi Johnston

5 Answers

  • 6 votes

Signs

Same

Subtract:

SSS

Answered Sat 4th June, 2011 @ 16:48 by Kelly:)
  • 3 votes

Your trying to get rid of either x or y, so if it was -y and y you would add to get rid of y but if it was 2y and 2y you would minus tog et rid of y ;)

Answered Fri 3rd June, 2011 @ 14:28 by Lamise Hassan
  • 1 vote

It doesnt make a difference. But the aim is to get rid of one of the letters, either x and y

For example: 1) 2x - y = 3   2) 2x + y = 4

You can either subtract and get rid of the x variable or add and get rid of the y variable

Answered Sat 4th June, 2011 @ 13:59 by Michelle
  • 1 vote

whatever your trying to get rid of (x or y), if the signs are the same you minus, if they are different you add

Answered Sat 4th June, 2011 @ 15:39 by Pui Pui
  • 1 vote

Signs

Different

Add

SDA

Answered Sat 4th June, 2011 @ 21:56 by Pwincessxx