Please help me understand this question, thanks!

Question

10. Write the slope-intercept form of an equation of the line perpendicular to the line in Exercise 7 with a y-intercept of -3.

7. (4, -9), (-3, 2)

Answer 1

slope for the the 2 given points
=(2+9)/(-3-4) = 11/-7

so the slope of a perpendicular line is +7/11

so for a slope of 7/11 and a y-intercept of -3 the equation is

y = (7/11)x - 3