Maths CIE 2013 oct/november Paper 21 help?!

[bunnyses]

Shear factor 2 x axis invariant and the answer for the pencil and pen was 20, which many of my classmates got too

its not 20 it was 3.75 something like that

 

[tonysingh]

It was 20.

 

[snipex]

It was def 20, and the paper was really easy el7

 

[tonysingh]

What was the answer to the "express x in terms of n " question ?

 

[snipex]

Well thats the only question I got stuck in

 

[snipex]

I guess it was adding both the terms he gave to you in the ques

 

[tonysingh]

I substituted x into the first formula and merged the formula into the one below.

 

[snipex]

Well I actually did the same

 

[Michelle Chimmy]

hey guys im so stressed. how did people do the working for the pencil and pen question. I had said (x/2.50)+(x-14.5/0.5)=19 which the answer was faaar off and I knew it was wrong.

 

[snipex]

hey guys im so stressed. how did people do the working for the pencil and pen question. I had said (x/2.50)+(x-14.5/0.5)=19 which the answer was faaar off and I knew it was wrong.

For starters, your work is correct and if your answer is 20 then your answer is correct

 

[Michelle Chimmy]

I didn't get 20 I was struggling to make x the subject properly.

 

[snipex]

The way you began your question was right

 

[Michelle Chimmy]

do I at least get a mark for that equation?

 

[snipex]

I dont know how you worked out the answer in the end but I think you get at least 1 mark for the begining

 

[Michelle Chimmy]

I guess its better than nothing. how was I supposed to continue?

 

[snipex]

Well you get lcm for both terms , cross multiply then solve equation normally.

 

[Michelle Chimmy]

that is exactly what I did. I got (0.5x+2.5x-36.25/1.25)=19 which then became 3x+36.25=23.75 and then 3x=60 then omg it is 20 I cant belive I didn't get this right!!!!!!

 

[Michelle Chimmy]

NERVES GOT TO ME!!

 

[snipex]

that is exactly what I did. I got (0.5x+2.5x-36.25/1.25)=19 which then became 3x+36.25=23.75 and then 3x=60 then omg it is 20 I cant belive I didn't get this right!!!!!!

Well you didnt get it correct because it is3x-36.25=23.75(not +36.25)

 

[Michelle Chimmy]

I had actually added it. it was a typo