Question

describe how do you know if two lines are parallel if all you knew were the equations of the two lines

Answer 1

Two lines are parallel if they intersect.

Answer 2

Explanation:

Put what you are given in the form of

y = mx + b

If both equations have the same m, the lines are parallel. For example

y = 4x + 10

y = 4x + 20

These two lines are parallel.

However

y = 8x + 40

y = 4x + 10 are not parallel even though it looks like m could be made the same by taking out 4 in each. Check them out on the graph below.