Determine whether the lines are parallel, intersect, or coincide.
y=2x+5
y=2x-1

Question

Determine whether the lines are parallel, intersect, or coincide.
y=2x+5
y=2x-1

e.mccormick · Answer

Know what parallel, intersect, and coincide are and how they relate to the slope and intercept?

anonymous · Answer

yes

e.mccormick · Answer

OK, then what about this is giving you trouble?

anonymous · Answer

I don't know how to find the answer.

e.mccormick · Answer

Hmmmm ...  OK.  Then tell me how the slope and intercept relate to those three.  See, if you know, it exposes the answer.

e.mccormick · Answer

The short form is this:

Parallel:  Same slope, different intercepts.
Coincide:  Same slope, same intercepts.
Intersect: Different slopes.
Perpendicular: Different slopes that are the negative inverse of each other.

So look at the slope and intercept of your two lines.  Which of those applies?

anonymous · Answer

Parallel?

e.mccormick · Answer

YEP!

anonymous · Answer

I get it now, Thanks!

e.mccormick · Answer

They have the same slope, 2, and different inercepts 5 and -1, so they are parallel!

e.mccormick · Answer

np.  have fun!