Elimination occurs when you add or subtract each equation in order to isolate one variable.
In this case, the first equation can be multiplied by 3. This will get you a -12x in one equation and a 12x in the other.
-12x - 9y = -42
12x + 5y = 2
Now add the second equation to the first to cancel the -12x and 12x.
-4y = -40
Now divide both sides by -4.
y = 10
Plug in the y value for one of the original equations and solve.
12x + 5(10) = 2
12x + 50 = 2
12x = -48
x = -4
Your solution set is (-4, 10)