Explanation:
step 1. graph f(x) = 2x + 6
step 2. y = mx + b. (slope intercept form)
step 3. b = 6 which is the y intercept so put a dot on (0, 6) or on the y axis at 6
step 4. m = 2 so put another dot up 2 and over to the right 1 from the y intercept
step 5. draw a line through your 2 points and you are done.