To surf the internet for 15 minutes at an airport, it costs $4.05. For 40 minutes, it costs $5.80. Write and solve a linear equation to find the cost for surfing the web for one hour.

The input to the function is x and the output is y. write the function such that x can be a vector (use element-by-element operations). a) use the function to calculate y(-1.5) and y(5). b) use the function to make a plot of the function y(x) for -2 ≤ x ≤ 6.