A student is attempting to simplify the expression below. Sample mathematical work is shown. Which statement best applies to the sample mathematical work?

Given (a+b - 2 * (ab-a)), I first apply the distributive property, which yields the expression a + b – 2ab + 2a. I can then collect like terms: since a + 2a = 3a, I have the expression 3a + b – 2ab as my final answer.
A.
The student failed to properly apply the distributive property.
B.
The student collected two or more terms that were not like terms.
C.
The student failed to collect all like terms.
D.
The mathematical work shown above is correct.

Question

A student is attempting to simplify the expression below. Sample mathematical work is shown. Which statement best applies to the sample mathematical work?

Given (a+b - 2 * (ab-a)), I first apply the distributive property, which yields the expression a + b – 2ab + 2a. I can then collect like terms: since a + 2a = 3a, I have the expression 3a + b – 2ab as my final answer.
A.
The student failed to properly apply the distributive property.
B.
The student collected two or more terms that were not like terms.
C.
The student failed to collect all like terms.
D.
The mathematical work shown above is correct.

jhonyy9 · Answer

ok so come we see it step by step

choice A. may be wrong ? like a first step the student applyed the distributive property - so this is correct or not ?

choices B. and C. are about collected like terms - how you think these may be wrong ?

choice D. how you think this work is correct ?