Question

Determine which of the line if any are parallel a (-1,-2) and (1,0) b (4,2) and (2,-2) c (0,2) and (-1,1)

1.a and b the slopes and the same
2 a and c the slopes are the same
3. b and c the slopes are the same
or a b and c the slopes are the same

Answer 1

2 a and c the slopes are the same

Explanation:

You want to know which lines are parallel, when each is defined by two points:

• a (-1,-2) and (1,0)
• b (4,2) and (2,-2)
• c (0,2) and (-1,1)

Slope

Lines are parallel when they have the same slope. The slope is the ratio of the difference in y-coordinates to the difference in x-coordinates.

A

Slope = (0 -(-2))/(1 -(-1)) = 2/2 = 1

B

Slope = (-2 -2)/(2 -4) = -4/-2 = 2

C

Slope = (1 -2)/(-1 -0) = -1/-1 = 1

Parallel

Lines A and C have the same slope, so are parallel (choice 2).