The error is in the Step 4 and the correct expression would be - 7.48b + 23
In the above question, it is given that
Margie's work for adding linear expressions but after checking her answer with the answer key, she solved it incorrectly.
We need to first identify the error and then make the corrections in it
Given (−3.12b + 12) − (4.36b − 11)
Step 1 −3.12b + 12 + (−4.36b) + 11
Step 2 −3.12b + −4.36b + 12 + 11
Step 3 (−3.12b + −4.36b) + (12 + 11)
Step 4 7.48b + 23
First, we'll find the error in Margie's linear expression solution
The error is in the last Step 4 of the Margie's solution
Now we'll write the correct solution
Given (−3.12b + 12) − (4.36b − 11)
Step 1 −3.12b + 12 + (−4.36b) + 11
Step 2 −3.12b + −4.36b + 12 + 11
Step 3 (−3.12b + −4.36b) + (12 + 11)
Step 4 - 7.48b + 23
Hence, the error is in the Step 4 and the correct linear expression would be - 7.48b + 23
To learn more about, linear expression, here
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