How many different four digit alarm codes can be formed for a house alarm? The first digit must be a 2, 4 or 9 and all the other digits can be any number and numbers can be repeated.

Given f(x) = 2x^2- 5x+1, determine the function value f(2). do not f(x) = in your answer

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.

Apasta salad was chilled in the refrigerator at 35° f overnight for 9 hours. the temperature of the pasta dish dropped from 86° f to 38° f. what was the average rate of cooling per hour?