provides further examples of common algebraic errors and argues that some errors arise
from correct pervious leaning.
For example, pupils who solve (x- 1) (× - 3) = 0 correctly with × - 1 = 0 or x - 3 = 0 will be puzzled why this correct Procedure leads to the wrong answers with (x - 1)(x - 3) = 5, for instance Suggest some ways to resolve this problem.