LET’S TRY ONE
Solve for x: 2x + y = 10, and x + y = 7.
3
Subtract the second equation from the first: 1x = 3, so x = 3.
Learning steps & teaching tips
Eliminate one variable to solve two simultaneous linear equations.
- Subtract corresponding sides when both equations have the same coefficient for one variable.
- Work through the example and explain why each operation is used.
- Estimate or use another method to check the result before choosing.
Try it together
Work with a partner: solve one example, explain the method, then change one number and predict what changes.
Subtract corresponding sides when both equations have the same coefficient for one variable.