I need some real help with this please guys, ok so here's the example given to me from tutor:

Example 2x+y= 1,x+ 3y= -7

Method 1 - add/subtract

2x+y= 1

x- 3y= 11

You can add or subtract. Adding will enable you to focus onx, subtracting will focus ony.

Perhaps the easiest is to add. BUT first of all you must scale the first expression by 3 to enable they’s to match, giving the zero count fory, you require.

So 6x+ 3y= 3 (Note each part has been x 3)

x- 3y= 11

Adding 7x= 14 (Note the zero count for y - this is what youx= 2 want to happen)

Substituting back into one of the previous expressions -

2(2) +y= 1, 4 +y= 1,y= -3

ANSWERx= 2,y= -3

My first problem is, from the example equations, how can it be re-arranged and make 11?!

I'm confused with this topic, thanks

ADY