If two lines have the same slope, they are parallel.
If the product of 2 slopes is -1, the lines are perpendicular.
10. The lines do not have the same slope, so they are not parallel.
3 * (-1) = -3. The product is not -1, so the lines are not perpendicular.
Answer: neither
11. 2/3 and -3/2 are not equal, so the lines are not parallel.
2/3 * (-3/2) = -6/6 = -1
The product of the slopes is -1, so the lines are perpendicular.
Answer: perpendicular
12.
Plot the points (2, 16) and (5, 40).
Draw a line though them.
Then you can use the slope formula to find the slope.
m = (y2 - y1)/(x2 - x1) = (40 - 16)/(5 - 2) = 24/3 = 8