Laura completed a 10-mile race in 90 minutes. She ran most of it, but she also walked a little bit. She knows that she usually runs at a pace of 8.5 minutes per mile and she usually walks at a pace
of 12 minutes per mile. Assuming that she kept these times during the periods of running and
walking during her 10-mile race, how many minutes did she spend running and how many minutes
did she spend walking? Write a system of equations, but do not solve.

Graph a triangle (xyz) and reflect it over the line y=x to create triangle x’y’z’. describe the transformation using words. draw a line segment from point x to the reflecting line, and then draw a line segment from point x’ to the reflecting line. what do you notice about the two line segments you drew? do you think you would see the same characteristics if you drew the line segment connecting y with the reflecting line and then y’ with the reflecting line? how do you know?