Potential Errors Found In Flashcards?

[user4494]

Hello! I believe I have found some potential errors in the coordinate geometry flashcards in Group 7.

If I am wrong and these are not errors, can you help be understand why my reasoning is flawed?

On the Parallel/Perpendicular Flashcard:
The fun fact states that “perpendicular lines always intersect and it’s possible for the intersection to occur at either the x or y intercept, but not both.” But what if they intersect at the origin? Would that not be considered intersecting at both the x and y intercepts? If not, why not?

Then; on the next slide System of Equations:
for the Substitution demonstration, 4x + y is in parentheses after the 9 in the substituted equation 5x + 9(4x + y). If this is correct, why are we including the y and not using (4x + 7)?

Im sorry if I misinterpreted or misunderstood the material as a mistake. Thank you for taking the time to help me understand.

[cylverixxx]

@user4494

The fun fact states that “perpendicular lines always intersect and it’s possible for the intersection to occur at either the x or y intercept, but not both.” But what if they intersect at the origin? Would that not be considered intersecting at both the x and y intercepts? If not, why not?

They intersect at the origin, no? Two lines can at most intersect at one point.

@user4494

Then; on the next slide System of Equations:
for the Substitution demonstration, 4x + y is in parentheses after the 9 in the substituted equation 5x + 9(4x + y). If this is correct, why are we including the y and not using (4x + 7)?

Would be helpful if you could post a picture of whatever you’re referring to here

[user4494]

[cylverixxx]

Yes, it’s a typo and it should be 4x + 7 instead of 4x + y