Question

)Sandra is showing her work in simplifying (3.3 − 4.2) − 2.8 + 5.7. Identify any error in her work or reasoning.

Step 1: (3.3 − 4.2) − 2.8 + 5.7
Step 2: 3.3 + (− 4.2 − 2.8) + 5.7 (distributive property)
Step 3: 3.3 − 7 + 5.7
Step 4: 3.3 + 5.7 − 7 (commutative property)
Step 5: 9 − 7 = 2

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