Solve a multi-step Problem 6. From 1990 to 2001, the number of airports in the United States increased at a
relatively constant rate of 175 airports per year. There were 19,306 airports in the
United States in 2001.

a. How many U. S. airports were there in 1990?

b. Write an equation that gives the number of U. S. airports as a function of the number
of years since 1990.

c. Find the year in which the number of U. S. airports reached 19,500.

The length of a rectangle plus its width is 25 cm. the area is 156 square cm. what are the length and width of the rectangle? separate the answers with a comma.

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

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.