7-1 Additional Practice Adding And Subtracting Polynomials Answer Key Apr 2026

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

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.

The answer key for “7-1 Additional Practice: Adding and Subtracting Polynomials” sat face-down on Ms. Kellar’s desk, a silent judge. 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.

At the top, in blue ink, she had written: “You found the tower. +1 extra credit for honesty. I saw you look at the key and choose not to flip it.” He imagined the crisp, boxed answers: 1

Slowly, deliberately, Leo turned the page of his own notebook. He crossed out his first attempt on problem #7. He rewrote the subtraction vertically, aligning the like terms:

Ms. Kellar walked back in. “Time’s up. Pass your papers forward.” -2m² + 6m + 1

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.”

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

His heart thumped. 2y³ - 4y² - y + 7.