Prompt the user for an integer and test if it’s even or odd. Consider using the way Ruby rounds operations on integers when appropriate. Save this program in a file called compare.rb.

Modify compare.rb so that it:

Write a program that, given two points on a two-dimensional graph, outputs a message (string) if the line that connects them is horizontal or vertical, or if the slope is positive or negative.

Write a program to solve a system of two linear equations. A linear equation is a mathematical equation that describes a line through its slope (m) and its y-intercept (b), and it will take the form y = mx + b. Make sure to account for the cases where there is no solution or where there are an infinite number of solutions.

The unit pulse function, d[n], is very important in digital signal processing. This function is defined for integers only. It is equal to 1 when n is 0, and it is equal to 0 when n is any other integer. Write a program that prompts the user for an integer n, and returns the value d[n].

Prompt the user for integers x, y, and z. Implement the decision tree shown in Figure 4-6 based on the values using if statements. Output how many of the variables are greater than 0. Note: each right flow option represents false, and each left flow option represents true.