IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => IGCSE/ GCSE => Math => Topic started by: thukon on May 18, 2009, 05:26:22 am

Title: MATH SPECIMEN 4 HELP
Post by: thukon on May 18, 2009, 05:26:22 am

QUESTION 9 c iii... How do u do it? the mark scheme doesnt explain  properly or i dont understand it. ill read all the posts so please dont rush at the cost of a proper explanation hoping that ur post is at the top. thanks.

Title: Re: MATH SPECIMEN 4 HELP
Post by: Ghost Of Highbury on May 18, 2009, 05:39:44 am

okk..
heres d answer
from the above 2 questions
u can conclude
that
4f + 2g = 32/3
f  +  g  = 10/3     -->> (*2)
------------------------
  2f   +  2g = 20/3
 -
  4f  +  2g  = 32/3
--------------------------
      -2f      =  -12/3 = -4
therefore f = 2

substite and find the value of g

Title: Re: MATH SPECIMEN 4 HELP
Post by: nid404 on May 18, 2009, 05:40:22 am

 simultaneous equation.
f+g=10/3 X2----2f+2g=20/3
4f+2g=32/3

2f= 4 (32/3-20/3)
f=2

substitute value in equation to find g

f+g=10/3
2+g=10/3
g=10/3-2
g=1/1/3 or 4/3

hope its clear

Title: Re: MATH SPECIMEN 4 HELP
Post by: thukon on May 18, 2009, 05:42:28 am

ok thanks both of u. i used substitution method instead of elimination and that probably led to problems. its all clear now thanks.