How do you know (2,1) is a solution to 4x +y=9

Tell me how you got the it use the figures to answer questions 1and 2. in each diagram, line k is parallel to line l, and line t intersects lines. 1. based on the diagrams, what is the value of x? 2. how would you verify your answer for x?

He concluded that a heavier object dropped from the same height as a lighter object will land

Which rule describes the composition of transformations that maps △abc to △a”b”c