Oh, hey! I learned this last year!
A) SUBSTITUTION EQUATIONS
So, you will be given two equations.
Think carefully whether to substitute Equation 1 into Equation 2 OR Equation 2 into Equation 1.
Always look at two equations for like terms - you can see that both of these equations have a y.
Yes! You would rather substitute Equation 2 into Equation 1 because it's easier.
So, substitute the y in Equation 1 and it will give you
To expand the
So then it leaves you with 2x−3x+3=−1.
Send the +3 to the right hand side of equal sign and it will become -3.
[THAT'S NOT DONE YET! UNLESS IF YOU DON'T WANT FULL MARKS! (LOL)]
So now you've know that
So substitute 4 into
Option 1 (Substitute into Equation 1):
Now you have:
I'll show you how to do Elimination some other time.