question 1: D

explaination: if two lines have the same slopes (gradient), we can concluded to say that they are parallel to each other.

question 2: A

question 3: B

2. The slope of a line is the difference in the y-values divided by the difference in the x-values. The slopes of the two lines are:

Line1: (2,-2) and (-4,1), slope=(1- -2)/(-4-2)=3/-6=-1/2

Line2: (1,2) and (-3,4), slope=(4-2)/(-3-1)=2/-4=-1/2

see the answer for problem number one.

3. Same problem solving:

Line1: (-4,2) and (0,-4), slope=(-4-2)/(0- -4)=-6/4=-3/2

Line2: (4,3) and (-5,-3), slope=(-3-3)/(-5-4)=-6/-9=2/3

Lines that have the negative inverse of each other are perpendicular.