Answer:
Step-by-step explanation:
Given: 4 - 9x +21
Factorizing this expression, we have;
4 -3(3x - 7)
i. Chang's expression: 4 - 3(3x + 7)
This is not an equivalent expression, because by expansion of the bracket, the expression gives: 4 -9x -21
ii. Benjamin's expression: 4 + 3(3x + 7)
This is not an equivalent expression, because by expansion of the bracket, the expression gives: 4 +9x +21
iii. Habib's expression: 4 + 12x
This is not an equivalent expression, because the expression is not related to the given question
Comparing the three student's answers with the appropriate expression, none of the student's is an equivalent expression.
This expression that is equivalent to the given question is;
4 -3(3x - 7) = 4 -9x + 21