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.

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

Keep doing each step manually, and see where it slips up:
−7.9+8.2−3.4+2.1=−1

−7.9+8.2+(−3.4)+2.1=−1

−7.9+(−3.4)+8.2+2.1=−1

(−7.9+(−3.4))+(8.2+2.1)=−1

−11.3+10.3=−1

Answer 2

So if you haven't noticed
there are no errors

Answer 3

ok but what about for Write feedback to Arlene explaining the mistake she made and how to correct her work.

Answer 4

@robtobey

Answer 5

Can you help?

Answer 6

Try answering the question and see where an error shows up, like @ChrystalC said :)

Answer 7

she said there are no errors @RainbowBrony555

Answer 8

@UnkleRhaukus can you help?

Answer 9

i don't see any errors

Answer 10

Theres no errors, @KAKES1967

Answer 11

ok so how would i go about this part though > Write feedback to Arlene explaining the mistake she made and how to correct her work. i would do nothing right?

Answer 12

I think so

Answer 13

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
the properties in steps 2 & 3 are misidentified