Dennis let go of a penny at the top of a well, and the penny fell straight down to the bottom of the well. The top of the well was 1\dfrac{1}{2}1 2 1 1, start fraction, 1, divided by, 2, end fraction meters above ground. The bottom of the well was 111111 meters below ground. The following equation describes this situation. \quad 1\dfrac{1}{2} + \left(-12 \dfrac{1}{2} \right) = -111 2 1 +(−12 2 1 )=−111, start fraction, 1, divided by, 2, end fraction, plus, left parenthesis, minus, 12, start fraction, 1, divided by, 2, end fraction, right parenthesis, equals, minus, 11 What does -12\dfrac{1}{2}−12 2 1 minus, 12, start fraction, 1, divided by, 2, end fraction tell us?