Answer:
y=5x+21
Explanation:
right now we know y=5x+b, so all we need is b.
graphing it on paper starting at (-4,1), you can go up 5, right 1 because your slope is 5.
you'll get (-4,1) (-3,6) (-2,11) (-1,16) (0,21)
Once you reach x=0, your intecept is 21, completing the slope intercept form, making it y=5x+21.