Demand for a particular good is given by the following equation: Q = 25 - 0.5P. What is the price elasticity of demand at the point (Q = 20, P = 10)? Type the answer in decimal form rounded to the nearest hundredth. For example, if your answer is negative one half, type -0.50. If it is negative two thirds, type -0.67. If it is negative three and three quarters, type -3.75.