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!
1. Substitute 3 in for the X to see if both expressions are equivalent. Remember to follow the order of operations.

3x + 8

3() + 8

+ 8




x + 3 + 2x + 5

+ 3 + 2() + 5

+ 3 + + 5



The two above expressions are equivalent or not equivalent?


2. Substitute 2 in for the X to see if both expressions are equivalent. Remember to follow the order of operations.

10 - 4x

10 - 4()

10 -





2(5 - 2x)

2[5 - 2()]

2(5 - )

2()



The two above expressions are equivalent or not equivalent?

3. Substitute -2 in for the X to see if both expressions are equivalent. Remember to follow the order of operations. Watch out for the negatives!


3x + 4 + 2x

3() + 4 + 2()

+ 4 +




6x + 4

6() + 4

+ 4



The two above expressions are equivalent or not equivalent?