Question

1)The graph below shows a line segment PQ:

Which of the following equations best represents the line segment PQ?

y = -3x + 2
y = -2x + 1
y = -3x - 2
y = -2x - 1

Answer 1

Let the equation of the line be
y = mx + c

The line has a y-intercept of 1. Therefore, c = 1.
The equation for the line is
y = mx + 1.

The line passes through (0,1) and (1,-1). Therefore its slope is
m = 2/-1 = -2.
The equation of the line is
y = -2x + 1

Answer: y = -2x + 1