The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Could someone explain what's wrong in solving this simultaneous equation?



Could someone explain why the first try is incorrect and the second one is right (according to the mark scheme)?

Sorry for messy handwriting, after 5h of doing questions my hand is starting to deform.
Reply 1
Avatar for Zacken
Zacken
22
Original post by frostyy


Could someone explain why the first try is incorrect and the second one is right (according to the mark scheme)?

Sorry for messy handwriting, after 5h of doing questions my hand is starting to deform.


I'm confused, you've written two different simultaneous equations down?

For the first block, y=65y = \frac{6}{5} is correct and this gives you x=335x = \frac{33}{5}. This is correct.
Original post by frostyy


Could someone explain why the first try is incorrect and the second one is right (according to the mark scheme)?

Sorry for messy handwriting, after 5h of doing questions my hand is starting to deform.


-120 + - 45 =/= -75.
(edited 8 years ago)
Original post by frostyy


Could someone explain why the first try is incorrect and the second one is right (according to the mark scheme)?

Sorry for messy handwriting, after 5h of doing questions my hand is starting to deform.


In the second one just check the -120 + -45
Original post by kingaaran
-120 + - 45 =/= -75.


You beat me to it.
Original post by maggiehodgson
You beat me to it.


:wink:
Reply 6
Avatar for frostyy
frostyy
OP
17
Original post by kingaaran
-120 + - 45 =/= -75.



the answer to a) is 4y - 3x - 15 = 0

according to the mark scheme, in b), x = 3

wtf?
Original post by frostyy

the answer to a) is 4y - 3x - 15 = 0

according to the mark scheme, in b), x = 3

wtf?


Hmm, in your second bit of working, have you copied down the equation correctly?

Edit: And in the first one for that matter?
(edited 8 years ago)
Reply 8
Avatar for Zacken
Zacken
22
Original post by frostyy

the answer to a) is 4y - 3x - 15 = 0

according to the mark scheme, in b), x = 3

wtf?


Yes, that's correct. Why?

Your second equation should either be 4y−3x−15=04y - 3x - 15 = 0 or −4y+3x+15=0-4y + 3x + 15 = 0.
(edited 8 years ago)
Original post by frostyy

the answer to a) is 4y - 3x - 15 = 0

according to the mark scheme, in b), x = 3

wtf?


in your first workings you are not using 4y - 3x -15, I think
Reply 10
Avatar for frostyy
frostyy
OP
17
Thank you for all the help.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you