## Algebra 1: Common Core (15th Edition)

(-2,3)(0,-1)(2,1) Find the rate of all three points by using the slope formula ($\frac{b1−b2}{a1−a2}$). DE=$\frac{3-(-1)}{-2-0}$=$\frac{4}{-2}$=-2 EF=$\frac{-1-1}{0-2}$=$\frac{-2}{-2}$=1 ED has the rate of -2 and EF has the rate of 1. They are different so they are different lines.