Find the equation of the line parallel to the x-axis with the same y-intercept as y = 2x - 7.

The x-axis is the horizontal axis.  A perfectly horizontal line that has no steepness at all. No slope.  Or we could say that it has a slope of 0.  A perfectly horizontal line goes through the y-axis at a specific point and never leaves that y value.  x values can stretch from negative to positive infinity, but that y value remains the same because our line is horizontal.  The y-intercept of our line is -7.  Therefore, the place on the y axis the horizontal line goes through is at -7.  So the equation for this line is y = -7.