Substitution

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!


Work out the value of the following expressions when a = 3, b = 4 & c = 5.

Example ab+c = 3x4 +5 = 12+5 =17
Don't forget BIDMAS!

1. a + b =

2. c + a – b =

3. 2a=

4. 5b=

5. 7c =

6. ac=

7. 3ab=

8. 3abc=

9. b2 – a2=

10. 4c2 + 3b2 =

11. 2a2 + c2 =

12. 5b/2 =

13. 6a/9=

14. 3b/(2a)=

15. abc/(5b)=

16. 44/b=

17. 15/a=

18. 20/b=


Work out the value of the following expressions when x = 3, y = – 2 & z = – 4.
Example
3y/x = -6/3 = -2

1. x + y=

2. y + z =

3. y + x – z=

4. 10z =

5. 5y=

6. xy=

7. 2xz=

8. xyz=

9. x2 =

10. z2 + y2 =

11. 3y2 =

12. 4z2 + 3y2 =

13. 2x2 + z2 =

14. 3yz/(4x) =

15. 20/z=

16. 44/y=

17. 3y/(2x) =

18. 4xy/(2z) =