Ineed with questions 12-15. you can choose one but if you can give me all the answers i will mark you brainliest

For lines to be parallel, the slopes have to be the SAME.

For lines to be perpendicular, the slopes have to be the exact opposite. (opposite sign and number)

For example(perpendicular):

slope is 2

the perpendicular slope is -1/2

slope is -4/5

the perpendicular slope is 5/4

12. line a and b are perpendicular

13. Line a: y = 3/5x + 1

Line b: y = 3/5x - 2/5

Line c: y = 4/6 + 5/3x

line a and b are parallel

14. Line a: y = 3x + 6

Line b: y = 6 - 3x

Line c: y = 2/3x + 6

Neither, none of them are parallel or perpendicular

15. Line a: y = -2/3 + 4/3x

Line b: y = -1/4 - 3/4x

Line c: y = 5 + 3/4x

line a and b are perpendicular