Answer:
If two lines are parallel, then they have the same gradient.
Explanation:
L is y=3x-2
L*2 is 3y-9x+5=0
The gradient for the first equation is 3
We need to rearrange the second equation and see if it has the same gradient as the first equation.
L*2 is 3y-9x+5=0
3y = 9x - 5
L*2 y = 3x - 5/3
As you can see, once you rearrange and simplify the equation, the second line has the same gradient as the first equation.
So that means these two lines are parallel