The equation y = 7/4x - 1 is in slope-intercept form, with a slope of 7/4 and a y-intercept of -1.
To graph it, you need to locate the point (0, -1) - the y-intercept -, and then use the slope to find another point. From (0, -1) you have to move 4 units to the right, and 7 units up, reaching the point (4, 6). Then, you have to draw the line that passes through theses points, as follows: