To verify which step contains an error using the Commutative Property of Addition, let's examine each step closely.
Given Expression:
Verify: \[ 8 + x^2 + 17x - x^2 + 4 = 10 + 4x^2 + 10x - 4x^2 + 2 + 7x \]
Steps
Step 1: \[ 8 + 4 + x^2 - x^2 + 17x = 10 + 2 + 10x - 4x^2 + 7x + 4x^2 \]
Step 2: \[ 8 + 4 + 17x + x^2 - x^2 = 10 + 2 + 4x^2 - 4x^2 + 10x + 7x \]
Step 3: \[ 12 + 17x + x^2 = 12 - x^2 + 17x \]
Analyzing Each Step
- Step 1: Rearrangement of terms is made but the operations look appropriate, as they group like terms together.
- Step 2: Again grouping like terms, however, we notice in the right side, \(4x^2\) and \(-4x^2\) should cancel out.
- Step 3: The left side simplifies correctly to \(12 + 17x\). On the right side, having \(-x^2 + 17x\) seems suspicious since there’s not a corresponding \(x^2\) term on the left.
Identifying the Error
The critical error seems to be in Step 3 since it incorrectly implies:
- The left side simplifies to \(12 + 17x + x^2\) while the right side simplifies to \(12 + 17x\) without any \(x^2\) term present.
Thus, the answer is: Step 3 contains the error.