## 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. Kat Yong Jie the first to answer said and4/29/2011 08:10:00 PM

1. No. 3ab stands for 3 x a x b and not 3a + b. Instead she should not had simplified it, as it already is.

2. No. 6st stands for 6 x s x t and not 2s + 4t. Instead she should not had simplified it, as it already is.

2. 1.No, she did not. 3a+b cannot be futher simplified since they are unlike terms. 3ab is 3a x b not 3a+b. Thus, the answer for the first equation is 3a+b not 3ab.

2.No,she did not. 2s+at are unlike terms thus they cannot be added together which means the expression cannot be futher simpified. So, the answer is 2s+4t not 6st.

3. No. 3a+b= 3 x a + b
it is not 3ab because it means3 x a x b
No. 2s + 4t = 2xs + 4xt.
it is not 6st because it means 6xsxt

4. 3a+b is not equal to 3ab. It is not possible to add items of different units, just like how it is not possible to add 3 apples and 1 pear.

2s+4t is not equal to 6st. It is not possible to add items of different units, just like how it is not possible to add 3 apples and 1 pear.

5. 1. It is wrong, 3ab is multiplication, while 3a+b is addition. It cannot be simplified any further since there are no like terms.
2. It is also wrong, it has the same mistake. 6st is multiplication, while 2s+4t is addition. It cannot be simplified any further because there are no like terms.

6. No. 3ab is 3 x a x b. 3a + b is 3 x a + b.
No. 6st is 6 x s x t. 2s + 4t is (2 x s) + (4 x t)

7. Great attempt please make reference to commutative laws of addition and multiplication

8. 1) 3a + b is equals to 3a plus b but 3ab is equals to 3 x a x b.

2) 2s + 4t is equals to 2s plus 4t but 6st is equals to 6 x s x t.

both are incorrect.