how could i write an equation of a line from the given information?

Question

a: the slope and the y-intercept of the line
b: two points on the line
c: the slope of the line and a point on the line that is not the y-intercept

(each letter should have a different answer)

Answer 1

a. y = mx + b
b. (y - y1)/(x - x1) = (y2 - y1)/(x2 - x1)
c. (y - y1)/(x - x1) = m