9.3: Solving Simultaneous Linear Equations by Substitution Method

1) Lesson Objectives:

You should be able to 

• solve simultaneous equations by Substitution Method

• to check you answer using a calculator

Please watch the video lessons after this section.

Solve the following simultaneous equations:

x + 3y  =  5

2x - 5y = -12

Steps:

1. Label both equations as (1) and (2)

2. Choose a variable that have coefficient 1.

3. Make sure the variable is the subject of the equation

4. Substitute the new equation into the other equation

5. Once you find one variable, remember to substitute and find the other variable

6. You must have 2 values, one for each variable as your answer 

7. Check if you answer is correct by using your calculator