Solve the equation for y in terms of x, and replace y function notation f(x). then find f(3).

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

What is the difference between the equations of a vertical and a horizontal line?

Let x = a + bi and y = c + di and z = f + gi. which statements are true?