Using Elimination
Elimination is used when it is easy to make one of the equation in the system have opposite coefficients. These opposite coefficients are essential to this method. Without these opposite coefficients, changing the equation will be a waste of time, and this method will not work. It is very easy to make one of these equations have opposite coefficients, all you need to do is multiply the whole equation by the number that makes the variable's coefficient opposite of the coefficient of the same variable on the other equation. You have to multiply all the items in the equation. Next, you have to add the equation together, by putting the equations on top of each other. The same way, when you add two twodigit numbers together. After you add the equations you are left with a one variable equation. You solve the equation to find the numerical value of that one variable. Finally, you plug that numerical value into one of the equations, and you solve for the variable that you eliminated.
Comparing Elimination and Substitution
Elimination

Substitution
