Question

Line p contains points A(–7, –9) and B(4, 0). Line q is parallel to line p. Line r is perpendicular to line q. What is the

slope of line r? Explain.

Answer 1

(-7,-9)(4,0)
slope = (0 - (-9) / (4 - (-7) = 9/11...line P slope

line q is parallel....parallel lines have the same slope, so line q has a slope of 9/11.

line r is perpendicular to line q....that means line r will have a slope of -11/9. The reason is because perpendicular lines will have negative reciprocal slopes. To find the negative reciprocal of a number, just flip the number and change the sign. So, 9/11, when flipped and the sign changed is -11/9. <==