Question

Help!!! Please
Arlene is showing her work in simplifying −7.9 + 8.2 − 3.4 + 2.1. Identify any errors in her work or in her reasoning. Write feedback to Arlene explaining the mistake she made and how to correct her work.


Step Work Reasoning
−7.9 + 8.2 − 3.4 + 2.1 Original problem

1 −7.9 + 8.2 + (−3.4) + 2.1 Additive inverse
2 −7.9 + (−3.4) + 8.2 + 2.1 Associative property
3 (−7.9 + (−3.4)) + (8.2 + 2.1) Commutative property
4 −11.3 + 10.3 Simplify
5 −1 Simplify

Answer 1

@welshfella

Answer 2

@welshfella can you help me?

Answer 3

Please

Answer 4

i know that the error is in step 2 and 3

Answer 5

I cant help you with all of this as I didn't do these properties when i was in school. but i can see some of the problems
line 2:- +(-3.4) has been moved in front of the 8.2 That is the Commutative Property - NOt the associative

Answer 6

Yes 3. should be the Associative property.

Answer 7

OK?

Answer 8

Yes :)