parallel and perpendicular lines

Question 1

how do you work out perpendicular line?

Answer 1

negative reciprocal

Question 2

how do you work out parallel lines?

Answer 2

same gradient

Question 3

how do you work out the line and the points it passes through?

Answer 3

substitute values given into the equation and work out C

y = 2x + c
passes through point (1,10)
10 = 2 x 1 + c
c = 8