7-1 Additional Practice Adding And Subtracting Polynomials | Answer Key

Leo passed his. He hadn’t checked the key. He had no idea if his answer was right.

He distributed the negative: 5y³ - 3y³ = 2y³. 0y² - 4y² = -4y². -2y - (-y) = -2y + y = -1y. 1 - (-6) = 7. Leo passed his

Now, during the last five minutes of class, Ms. Kellar had stepped into the hall to take a call. The answer key was right there. One quick flip. A single glance. He distributed the negative: 5y³ - 3y³ = 2y³

His hand hovered.

Ms. Kellar walked back in. “Time’s up. Pass your papers forward.” 1 - (-6) = 7

He imagined the crisp, boxed answers: 1. 4x² - 2x + 2. 2. -2m² + 6m + 1. The certainty of it. No more eraser shavings on his jeans. No more gnawing doubt.

But then he remembered the day Ms. Kellar had handed back his last quiz. She hadn't just written a grade. She’d written: “Leo – you understand the idea . You just keep dropping the negative sign. Try stacking them vertically, like a tower.”