Marco looked at her for a long moment. Then he did something unexpected. He pushed the textbook aside, took a fresh sheet of paper, and drew a rectangle.
The red warning light on the wall pulsed faster. Two minutes remaining. explain
He drew an equal sign and a blank square on the other side of the paper. Marco looked at her for a long moment
Lena had been staring at the same equation for three hours. It stared back—a serene, untroubled collection of symbols that meant nothing to her. ( x^2 + 5x + 6 = 0 ). Her tutor, a patient graduate student named Marco, had already shown her the quadratic formula three times. She had memorized it. She could recite it in her sleep. But she didn't understand . The red warning light on the wall pulsed faster