Standard form is another way to show the same information as slope-intercept form. It is shown as , being the y-intercept and being the slope.
The y-intercept is at (0,3) making it 3. The slope is or 1. Put -1 in place of and 3 in place of . The reason you put -1 in place of instead of 1 is because when you change the equation to slope-intercept form, you would take -1 to the other side of the equation and change the sign during the process.