Simultaneous Linear Equations

Question 1

What are the steps for solving by substitution?

Answer 1

1. Solve one of the equations for one of the variables (doesn’t matter which one).
2. Substitute the expression from part 1 into the other equation.
3. Solve the new equation for the remaining variable.
4. Go back to the very first step and plug in the value you found out in part 3 to solve for the other variable.

Question 2

What are the steps to solving by elimination?

Answer 2

1. Rearrange the and stack the equations so the variables line up.
2. Multiply one or both equations by whatever we need to so that one of the variables has the same number but different signs.
3. Add the two equations together and solve for the remaining variable.
4. Go back to the very first step and plug in the value you found out in part 3 to solve for the other variable.