You probably already know that the inverse of add is subtract (to undo +3 you would -3) and the inverse of multiply is divide

(Also, to undo subtract you add, to undo divide you multiply)

Have a go at the questions below in your blue book:

NB On question one, you will have to find a function that works for all of the inputs for a function machine eg in 1c 'add 7.5' won't work because it only works for the first one, it won't work for 6 - so you need to try out multiplying

MARK YOUR ANSWERS AS YOU GO TO CHECK YOU ARE UNDERSTANDING THIS (Answers are at the bottom of this page).  Upload a  photo of your work in Firefly before the end of the lesson.

On qu 2 sometimes it will help to think about inverse functions - eg to undo 'multiply by 4' you can 'divide by 4'

Qu 3 - make sure you 'undo the last thing first' so in 3e you need to to -3 then divide by 2

Extra questions: