Question

6x = 3y - 9


y = 6x + 15


2y + 3x + 6 = 0


y = 2x + 3


x = 2y + 3

Answer 1

Here they are solved for y (slope-intercept form):

1) 6x = 3y - 9 -> 3y = 6x + 9 -> y = 2x + 3
2) y = 6x + 15 -> y = 6x + 15
3) 2y + 3x + 6 = 0 -> 2y = -3x - 6 -> y = -3/2 x - 3
4) y = 2x + 3 -> y = 2x + 3
5) x = 2y + 3 -> 2y = x - 3 -> y = (x - 3)/2 = 1/2 x - 3/2

Note: equations 1 and 4 represent the same line (y = 2x + 3).