LET’S TRY ONE
If f(x) = 2x + (3), what is f−1(11)?
4
Solve 2x + (3) = 11. Subtract 3, then divide by 2: x = 4.
Learning steps & teaching tips
Reverse a nonconstant linear rule to recover an input.
- Undo addition or subtraction before undoing multiplication.
- 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.
Undo addition or subtraction before undoing multiplication.