Question

Matt is showing his work in simplifying (6.2 − 1.6) − 4.4 + 7.8. Identify any error in his work or reasoning. (5 points)

Step 1: (6.2 − 1.6) − 4.4 + 7.8
Step 2: 6.2 + (− 1.6 − 4.4) + 7.8 (commutative property)
Step 3: 6.2 − 6 + 7.8
Step 4: −14 − 6 = 8 (commutative property)
Step 5: 14 − 6 = 8

He wrote commutative instead of distributive in Step 4.
He wrote commutative instead of distributive in Step 2.
He wrote commutative instead of associative in Step 4.
He wrote commutative instead of associative in Step 2.

Answer 1

Can someone help me???

Answer 2

Major hint: moving parentheses is the associative, not commutative property. Which step does the parentheses moving occur?

Answer 3

Please review the commutative, associative, and distributive properties when you get a chance.

In step 2, they moved the parentheses from 6.2 - 1.6 to -1.6 - 4.4. This is an example of the associative property, not the commutative property. Therefore, they mislabeled associative as commutative in step 2.