Question

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.

Answer 1

Original problem: −7.9 + 8.2 − 3.4 + 2.1
Additive inverse: −7.9 + 8.2 + (−3.4) + 2.1
Associative property: −7.9 + (−3.4) + 8.2 + 2.1
Commutative property: (−7.9 + (−3.4)) + (8.2 + 2.1)
Simplify: −11.3 + 10.3
Simplify : −1

Answer 2

I'm really confused with this problem