Fatihul Ulum Community of Knowledge
Would you like to react to this message? Create an account in a few clicks or log in to continue.

Contoh Soal

2 posters

Go down

Contoh Soal Empty Re: Contoh Soal

Post  andy maulana Mon Feb 23, 2009 5:42 am

SyaBah wrote:ULANGAN I

1. 3x + y = 9
3x + 2y = 12
Hitung nilai x dan y !

Jawab:
a. Metode Eliminasi - Substitusi:

3x + y = 9 | dikalikan 2 | 6x + 2y = 18
3x + 2y = 12 | dikalikan 1 | 3x + 2y = 12 _

3x = 6
x = 6 : 3
x = 2

3 (2) + y = 9
6 + y = 9
y = 9 - 6
y = 3

Jadi (x,y) = (2,3)

b. Metode Matrix

3x + y = 9
3x + 2y = 12

Dijadikan bentuk matriks :

| 3 1 | | x | = | 9 |
| 3 2 | | y | | 12 |
A . X = B

Maka :
X = A-1 . B
X =
| d -b | . | 9 |
| -c a | | 12 |
(ad-bc)

| 2 -1 | | 9 |
| -3 3 | | 12 |
(3x2 - 1x3)

| 2x9 + -1x12 |
| -3x9 + 3x12 |
6 - 3

| 18 + (-12) |
| -27 + 36 |
3

| 6 |
| 9 |
3

| 2 |
| 3 |

Jadi (x,y) = (2,3)


2. 3x + 2y - z = 3
-2x + y + 3z = 5
4x - y - 2z = -1

kalau soal nomor dua jawabannya mana pak?
ko' ga' ada! Very Happy Very Happy
andy maulana
andy maulana
Pejuang
Pejuang

Jumlah posting : 74
Age : 33
Lokasi : jawa timur
Registration date : 13.02.09

Kembali Ke Atas Go down

Contoh Soal Empty Contoh Soal

Post  SyaBah Sat Feb 14, 2009 3:44 am

ULANGAN I

1. 3x + y = 9
3x + 2y = 12
Hitung nilai x dan y !

Jawab:
a. Metode Eliminasi - Substitusi:

3x + y = 9 | dikalikan 2 | 6x + 2y = 18
3x + 2y = 12 | dikalikan 1 | 3x + 2y = 12 _

3x = 6
x = 6 : 3
x = 2

3 (2) + y = 9
6 + y = 9
y = 9 - 6
y = 3

Jadi (x,y) = (2,3)

b. Metode Matrix

3x + y = 9
3x + 2y = 12

Dijadikan bentuk matriks :

| 3 1 | | x | = | 9 |
| 3 2 | | y | | 12 |
A . X = B

Maka :
X = A-1 . B
X =
| d -b | . | 9 |
| -c a | | 12 |
(ad-bc)

| 2 -1 | | 9 |
| -3 3 | | 12 |
(3x2 - 1x3)

| 2x9 + -1x12 |
| -3x9 + 3x12 |
6 - 3

| 18 + (-12) |
| -27 + 36 |
3

| 6 |
| 9 |
3

| 2 |
| 3 |

Jadi (x,y) = (2,3)


2. 3x + 2y - z = 3
-2x + y + 3z = 5
4x - y - 2z = -1
SyaBah
SyaBah
Penjelajah
Penjelajah

Jumlah posting : 27
Age : 40
Lokasi : Tanggul - East Java
Registration date : 11.02.09

http://xipunx.100webspace.net/

Kembali Ke Atas Go down

Kembali Ke Atas

- Similar topics

 
Permissions in this forum:
Anda tidak dapat menjawab topik