basic math
posted by kchik
An education fund allocates RM10,000 to help 100 students from form three, form five and form six in a school. Each form three student receives RM80, each form five student receives RM120 and each form six student receives RM160. The number of form three students that receive the aid is twice the number of form five students.
(a) Form a system of linear equations from the above information.
(b) Hence, determine the number of students for each form that receive the aid by using matrices.

Reiny
Form three students  x
form five students  y
form six students  100xy
80x + 120y + 160(100xy) = 10000
80x + 120y + 16000160x160y = 10000
80x  40y = 6000
2x + y = 150
but it said:
x = 2y
2(2y) + y = 150
y = 30
x = 2y = 60
remaining students = 1003060 = 10
I did not use matrices on such a simple problem because solving it was so much easier using the above method,
but.... if you have to use matrices
our two equations are:
2x + y = 150
x  2y = 0
2 1 150
1 2 0 >
4 2 300
1 2 0 >
1 2 0
4 2 300 > add
1 2 0
5 0 300
1 2 0
1 0 60
from the last x=60
in 1st: 602y=0
2y=60
y=30
etc
Respond to this Question
Similar Questions

Music
What musical form preceded the sonataallegro form, and is the sonataallegro form still being used today? 
math
Can you tell me if this is the correct way to write in standard form: 1. Fiftyfour million, six and six hundredths: 54,000,006.06 2. Thirtythree million, five and five hundredths: 33,000,005.05 
math
I'm sorry I was unable to open your answer. My question was if you could tell me if the following is correct in standard form 1. fiftyfour million, six and six hundredths 54,000,006.06 2. thirtythree million, five and five hundredths … 
Math
What is the standard form and expanded form of Five Thousand One Hundred Fifty Three? 
Chemistry
(1) Which of the following clusters of orbitals would form the shape trigonal bipyramidal and would also be possible within the valence shell of an atom? 
stats
suppose you are to form a scatterplot oby collecting data for the given pair of variables. determine the likely direction form and strngth. Student: high grade point average, student: studying consistency 
Math help, anyone?
Solve the proportion. Where necessary, round to the nearest hundredth. Plz help i really need 2 get this in!! 11. 9/10 = x/10 9 *** 90 10 100 12. x/4 = 6/7 168 0.21 28 3.43 13.Write the ratio as a fraction in simplest form. 22:36 14. … 
statistics
Give the probability in decimal form (correct to two decimal places). A calculator may be helpful. Last semester, a certain professor gave 35 As out of 259 grades. If one of the professor's students from last semester were selected … 
math
Give the probability in decimal form (correct to two decimal places). A calculator may be helpful. Last semester, a certain professor gave 15 As out of 396 grades. If one of the professor's students from last semester were selected … 
Math
Every few days a student at a school will receive a souvenir such as a pencil or shirt. Every 24th day a student receives a souvenier. Every 56th day a student receives a souveiner and every 64th day a student receives a souvenier. …