Consider it like this: You plug in something for , and you follow the expression by multiplying by then adding , to get the corresponding output value . This equation is linear: , where is the slope (change in y over change in x) and is the y-intercept (where it hits the axis).
Your equation just has and . So, let's make a quick table. You need at least two points to make a straight line, and three points to make a curve. Let's do five points though for practice.
In a table it then looks like this:
And after plotting each point by looking at and , and moving to the right units and up units (if negative, move the opposite direction), we get: graph{4x + 3 [-2, 2, -5, 11]} Every point we put on the table should be visible if you look at this graph.