## Friday, April 29, 2011

### Chapter 4: Algebra... Help! What's Wrong?

Jane did the following:
• 3a + b = 3ab
• 2s + 4t = 6st
Do you think Jane applied the correct algebraic manipulations process?
If yes, please write down examples to show that her answer is correct.

If not, explain to Jane her mistakes and help her to correct.

1. She did not for both. This is so as she multiplied a and b in the first one and s and t in the second one. Thus, these answers cannot be further simplified and must thus remain the same.

2. Well done and the first to attempt. Make reference to the commutative laws of addition and multiplication.

3. Mr johari, I thought we did the question already? You posted it last time! o.O

4. she did not apply for both manipulations. 3a+b by itself cannot be simplified, the same goes to 2s+4t because both involve the addition of the most simplest algebraic expression. So the answer to both her questions are, ironically the two questions themselves.

5. She did not apply the algebraic manipulations as she did not comply with the term, like and unlike term. 3a+b. 3a and b are 2 different values. Hence they cannot be added to each other.

6. She did not apply the correct algebraic manipulations as both questions contain different values and cannot be added together

7. No, she did not apply the correct algebraic manipulations. That is why she got the wrong answers for both the questions. She had multiplied a and b for the first question. She not only multiplied s and t but also added 2 and 4 together.

3a + b = (3a+b)
2s + 4t = (2s+4t)

8. I think Jane did not apply the correct algebraic manipulations process, as they both cant be simplified further, as a and b are unlike terms, and cant be put together, same as for t and s.

9. Obviously not. Jane simply added two different units together. What she has written is just like saying 1cm+1m=1cmm which totally makes no sense both in terms of the units as well as that of the value. Thus, if the units are different, she should not add them up. In this case, the expression is in its simplest form

10. Both answer are wrong.She cannot further simplified two unlike terms.She has also times the two different units up together.

11. Both answers are wrong as a,b, as well as s,t are unlike terms. therefore, they cannot be simplified and cannot be put together.