The y-intercept is the point at which the graph intersects the y-axis. The graph will intersect the y-axis when x = 0.
Substitute 0 for x in the expression.
y = 6 + (−3)(0)
y = 6
The slope is the value that y increases or decreases when x increases by one.
Create a table of values or sketch the graph on graph paper.
You should notice that from x = 0 to x = 1 the y-value decreases by 3. What is the slope?