Find an equation of the line with the given slope and containing the given point. Write the equation in slope-intercept form.

13. Slope 3; (1, 2)

14. Slope 4; (5, 1)

15. Slope -2; (1, -3)

16. Slope -4; (2, -4)

17. Slope 1/2; (-6, 2)

18. Slope 2/3; (-9, 4)

19. Slope -9/10; through (-3, 0)

20. Slope -1/5; through (4, -6)