SUBSTITUTION
 what is the answer of  2x+2y=2
                                    2x+3y=-2 ?
  &
4x-2y=6
3x+2y=8 ?


Sagot :

Why is this in Chemistry?

Anyway.

In order to solve system of equations using substitution, remember these two steps:
1. Isolate a variable that you think will have a simplified equation.
2. Plug-in this variable on the next equation.

Let's make the first system as an example.

On the first equation, let us isolate x on the left hand side.
[tex]2x+2y=2 \\\\ 2x=2-2y\\\\ x=1-y [/tex]

Now that we have a value for x, we substitute that on the second equation.
[tex]2(1-y)+3y=-2\\\\ 2-2y+3y=-2\\\\ y=-2-2=-4[/tex]

Plugging that value of y on the first equation, we get:
[tex]2x+2(-4)=2\\\\ 2x-8=2\\\\ 2x=10\\\\ x=5[/tex]

Do the same with the second problem. Hope that helps.

If you're having problems dealing with the second problem, don't hesitate to message me. :)