PLEASE HELP! Carla and Jonah are working together to determine if quadrilateral CDEF with coordinates C(2, 3), D(1, 2), E(4, 1), and F(5, 3) has a right angle.

Carla sets up the following equations:
the slope of segment CD equals 2 minus 3 all over 1 minus 2
the slope of segment DE equals 1 minus 2 all over 4 minus 1

Jonah sets up the following equations:
the slope of segment CD equals 2 minus 3 all over 1 minus 2
the slope of segment EF equals 3 minus 1 all over 5 minus 4

Who is on track to get the correct answer and why?

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

Jane’s favorite fruit punch consists of pear, pineapple, and plum juices in the ratio 5: 2: 3. chapter reference how much punch can she make if she has only 6 cups of plum juice?