so here, the y-int is 8, so you draw your x and y axis and put a point on the y-axis at eight.
then you should know that the slope is rise/run, that is height/horizontal distance, so from the point on the y-axis, move 8 units up and 7 units acroos, and that will give you the second point. draw a line throught these two points. so your line should pass through (0,8) and (7,16)
if i was doing this, i wouldn't use the slope directly. i'd use the x-int and y-int. the y-int is already given, i can find the x-int by setting y = 0, then i'd find the point at which the graph cuts the x-axis and then draw a line though the x-int and y-int. so i'd draw the graph through (0,8) and (-7,0)
the graph is below. your method uses the red and blue dots, mine uses the red and green dots