Karen wrote the following steps to simplify the expression: 4 – (2x + 3x – 1).

Step Mathematical Statement Justification
0 4 – (2x + 3x – 1) Given
1 4 – 2x – 3x + 1 Distributive Property
2 4 + 1 – 2x – 3x Associative Property of Addition
3 (4 + 1) + (–2x – 3x) Associative Property of Addition
4 5 – 5x Combine Like Terms

Which step of justification is incorrect, and what should the justification for that step be to simplify the expression?

Question

Karen wrote the following steps to simplify the expression: 4 – (2x + 3x – 1).

Step	Mathematical Statement	Justification
0           	4 – (2x + 3x – 1)	Given
1	4 – 2x – 3x + 1	Distributive Property
2	4 + 1 – 2x – 3x	Associative Property of Addition
3	(4 + 1) + (–2x – 3x)	Associative Property of Addition
4	5 – 5x	Combine Like Terms

Which step of justification is incorrect, and what should the justification for that step be to simplify the expression?

anonymous · Answer

The answers:
Step 4; Distributive Property
Step 2; Commutative Property of Addition
Step 3; Associative Property of Multiplication
Step 1; Multiplication Property of Equality

anonymous · Answer

sorta same concept

anonymous · Answer

I think its the last choice, am I wrong?

anonymous · Answer

what do you think it is?  remember what i said before... the key is knowing what all these properties are...

anonymous · Answer

what is the difference between the Associative Property of Addition and the Commutative Property of Addition?

anonymous · Answer

associative is grouping and commutative is order....
for example:
associative property: a + (b + c) = (a + b) + c
commutative property:  a + b = b + a

anonymous · Answer

So wouldn't the answer be the second choice then?

anonymous · Answer

Because step 2 is in the wrong format and the right format would be Commutative Property of Addition since it is in order.

anonymous · Answer

hmm.. that's what i was thinking the answer is (the second choice)... but i'm having second thoughts....

anonymous · Answer

Why the second step is wrong in the way it is put.

anonymous · Answer

since everything else is in order, then yeah, i'd say the second choice is your answer...

anonymous · Answer

Well, thank you so much for your time and knowledge, you learn something new everyday day. Have a great day!

anonymous · Answer

yeah.. it's order.... second choice is your answer...

anonymous · Answer

Now onto learning parallel line proofs lol so much to do tonight...

anonymous · Answer

thank you for your great questions.. you have been a great student... and also made me rethink about those properties....:)

anonymous · Answer

The way my class teaches the math is hard for me to understand, you might be seeing some more of my posts if i don't understand them.

anonymous · Answer

no problem... (maybe..)    :)

anonymous · Answer

If I do have to do more posts, I hope you're still online :D