Question

For what value of k is the line through the points (3, 2k + 1) and (8, 4k − 5) parallel

to the x-axis?
(A) −1 (B) 3 (C) 2 (D) 0 (E) −4

Answer 1

B: 3

Explanation:

For the line to be parrallel to the x-axis, it means the slope is zero.

Thus;

(y2 - y1)/(x2 - x1) = 0

(4k - 5 - (2k + 1))/(8 - 3) = 0

4k - 5 - 2k - 1 = 0

2k - 6 = 0

2k = 6

k = 6/2

k = 3