What is Parallel to 6x - 2y = - 7 Perpendicular to 6x - 2y = - 7

-2x + 6y = 2

3x - y = 5

8x - 2y = 7

9x - 3y = 8

x + 3y = 12

and what is neither

Rearrange all of them in terms of y:

6x - 2y = - 7

y = (-6x - 7) / - 2

y = 3x + 7/2

1) - 2x + 6y = 2

y = 1/3x + 1/3

2) 3x - y = 5

y = 3x - 5

3) 8x - 2y = 7

y = 4x - 7/4

4) 9x - 3y = 8

y = 3x - 8/3

5) x + 3y = 12

y = - x/3 + 4

Parallel lines have equal gradients; the gradient is the coefficient of x.

2 and 4 are parallel to the original eq'n as they have 3x just like the original eq'n.

Perpendicular lines have gradients that are negative reciprocals of each other; they multiply to give - 1.

5 is the only one perpendicular to the original as - x/3 * 3 = - 1

1 and 3 are therefore neither.