Question

Solve by the elimination method. 9x+3y=-3 and 2x-3y=-8

Answer 1

By elimination, I guess you mean simultaneous equations?
You should put the 2 equations underneath each other.
When you do this, you'll see that there is a 3y in both the equations. Although one's positive and one's negative. To eliminate it, you have to add the 2 equations together - by this, I mean, add the x's column, and the y's column, and copy down the equals sign, and add the answers column.
What do you get after doing this?

Answer 2

9x + 3y = -3
2x - 3y = -8
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add this, and as you can see the y's cancel each other out, and you can solve for x. Once you have x, you can substitute what you got for x into either of the original equations, and solve for y. Once you know the variables, you can check it by substituting back into either of the original equations.