He distributed the negative: 5y³ - 3y³ = 2y³. 0y² - 4y² = -4y². -2y - (-y) = -2y + y = -1y. 1 - (-6) = 7.
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.”
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
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. He hadn’t checked the key. He had no idea if his answer was right. 1 - (-6) = 7
To Leo, it wasn’t a sheet of paper. It was the wall between a C- and a B+. He’d spent forty-five minutes wrestling with problems like “Add: (3x² + 2x - 5) + (x² - 4x + 7)” and the soul-crushing “Subtract: (5y³ - 2y + 1) - (3y³ + 4y² - y - 6).”
The subtraction was the worst. His friend Mia had whispered, “Just distribute the minus sign, Leo. Like a negative love letter.” But Leo kept forgetting to flip the last sign. I saw you look at the key and choose not to flip it
Ms. Kellar walked back in. “Time’s up. Pass your papers forward.”
(5y³ + 0y² - 2y + 1) -(3y³ + 4y² - y - 6)
His heart thumped. 2y³ - 4y² - y + 7.