A. Given a = 5, b = 1, x = 10, and y = 5, create a program that
outputs the result of the formula f = (a b)(x y) using a
single printf() function.
B. Create a program that uses the same formula above to output
the result; this time, however, prompt the user for the values
a, b, x, and y. Use appropriate variable names and naming
conventions.