If x can be any number, how many solutions are there for the equation? y = 7x – 1 * a. there are two solutions because there are two variables in the equation. b. there is only one solution because all equations have one solution. c. there is no solution because there are no values for the variables that make the equation true. d. there are many solutions because there are many values for the variables that make the equation true.

Choice D) There are many solutions (infinitely many)

Here are some solutions
(x,y) = (0,-1)
(x,y) = (1,6)
(x,y) = (2,13)

To generate a solution, you plug in any x value you want. For instance, if you plug in x = 2, you get,
y = 7*x - 1
y = 7*2 - 1
y = 14 - 1
y = 13
The values x = 2 and y = 13 pair up to form the solution (x,y) = (2,13)
There are no restrictions on what you can pick for x, so x can be any real number. That's why there are infinitely many solutions. All of the solutions are on the line y = 7x-1