Question 4 • Common Core Algebra I B-IC
Add the side lengths and multiply by 2: 2[(2x² − 16) + (−x² + 4x + 1)] = 2x² + 8x − 30. When x = 3, the perimeter is 2(3²) + 8(3) − 30 = 18 + 24 − 30 = 12 feet, so the correct choice is 2x² + 8x − 30; 12 feet.
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