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A level maths straight lines question

i cant see whats gone wrong here :frown: please could someone have a look

i first worked out the grad in terms of p, and formed a straight line equation. then i subbed in the coordinates of A and got the value of p=-1/3 which is wrong
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Original post by vix.xvi
i cant see whats gone wrong here :frown: please could someone have a look

i first worked out the grad in terms of p, and formed a straight line equation. then i subbed in the coordinates of A and got the value of p=-1/3 which is wrong.

Unless I'm mistaken, you've got a sign error between the line where you have 2p on one side and 8p on the other and the line where your replace that by 6p.
Original post by DFranklin
Unless I'm mistaken, you've got a sign error between the line where you have 2p on one side and 8p on the other and the line where your replace that by 6p.

Yeah that's what I think
Original post by vix.xvi
i cant see whats gone wrong here :frown: please could someone have a look

i first worked out the grad in terms of p, and formed a straight line equation. then i subbed in the coordinates of A and got the value of p=-1/3 which is wrong

You've changed the sign of 6p on the left but then changed both the numerator AND denom on the right - you need to only change the numerator.
Original post by DFranklin
Unless I'm mistaken, you've got a sign error between the line where you have 2p on one side and 8p on the other and the line where your replace that by 6p.

They x by -1 on the left but done that to the numerator and denom on the right.
Original post by Muttley79
You've changed the sign of 6p on the left but then changed both the numerator AND denom on the right - you need to only change the numerator.

sorry this sounds rly stupid but why only the numerator? if you multiply the entire thing by -1, then each sing (unless multiplied), changes right? x
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mqb2766
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Original post by vix.xvi
sorry this sounds rly stupid but why only the numerator? if you multiply the entire thing by -1, then each sing (unless multiplied), changes right? x

-2/(-2) = 1 = 2/2
Original post by vix.xvi
sorry this sounds rly stupid but why only the numerator? if you multiply the entire thing by -1, then each sing (unless multiplied), changes right? x

No - if you multiply both you've multiplied by 1 not -1
Original post by mqb2766
-2/(-2) = 1 = 2/2

thank youuu

Original post by Muttley79
No - if you multiply both you've multiplied by 1 not -1

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