Question

Colin was using the back of his book to check his homework answers. The answer that he had on his paper was −1/3 − (1/5 + 5/8). The correct answer, located in the back of the book, was −1/3 −1/5 + 5/8. Was Colin correct? Justify your response.

Answer 1

Answer: No. Colin was incorrect.

Explanation:

From the question, we are informed that the answer that Colin had on his paper was −1/3 − (1/5 + 5/8) while the correct answer, located in the back of the book, was −1/3 −1/5 + 5/8.

Colin was wrong because he didn't take into effect that the minus has affected the figures in the bracket. Therefore, 1/3 − (1/5 + 5/8) simply means 1/3 - 1/5 - 5/8.

He didn't realise that (-) × (-) = + which has resulted in the change of the sign beside 5/8 from positive to negative.