Page 16 - Top Class F5 - Mathematics (Chapter 2)

Mathematics Form 5 Chapter 2 Matrices

  7 8 –2 –4 5
5
2
17. Given that P = –1 4 , Q =  –3 1 6  , R =  2 3  and S = [7 –5], solve each of the following. PL 3
6 –3
5
2
  7 8 –2 –4 5
Diberi P = –1 4 , Q =   , R =   dan S = [7 –5], selesaikan setiap yang berikut.
6 –3 –3 1 6 2 3
Example (a) QP (b) PR
2
5
PQ –3 1 6   2 5
7 8 –2
2 5 =   –1 4  –4 5 
–1 4
–1 4  7 8 –2  6 –3   2 3
  –3 1 6 6 –3
6 –3 =  14 – 8 – 12 35 + 32 + 6  –8 + 10 10 + 15
 14 – 15 16 + 5 –4 + 30  –6 – 1 + 36 –15 + 4 – 18 =  4 + 8 –5 + 12 
= –7 – 12 –8 + 4 2 + 24  –6 73  –24 – 6 30 – 9
42 + 9 48 – 3 –12 – 18 = 29 –29 2 25

 –1 21 26  = 12 7 
= –19 –4 26 –30 21
51 45 –30

(c) SR (d) R (e)
2
 –4 5   –4 5 –4 5  [7 –5]  7 8 –2 

[7 –5]
2 3 2 3 2 3 –3 1 6
= [–28 – 10 35 – 15] 16 + 10 –20 + 15 = [ 49 + 15 56 – 5 –14 – 30]
= [–38 20] =  –8 + 6 10 + 9  = [64 51 –44]
=  26 –5 
–2 19

18. Calculate the value of x and of y for each of the following. PL 3
Hitung nilai x dan nilai y bagi setiap yang berikut.

Example x 3y
(a) [4 –5]   = [6 28]
 x 1 4 2 15 4  2x y
  
=
–7 –14
2y 3 3 y
[4x – 10x 12y – 5y] = [6 28]
 4x + 3 2x + y   15 4  4x – 10x = 6 , 12y – 5y = 28
=
–7 –14
8y + 9 4y + 3y
–6x = 6 7y = 28
4x + 3 = 15 , 8y + 9 = –7 x = –1 y = 4
4x = 12 8y = –16
x = 3 y = –2


 3 x 2x –3   y –5     –2 –10 
–2
(b) –1 5 1 4 = 3x 23 (c) 3x [1 y] = 6 30
 6x + x –9 + 4x   y –5   –2 –2y   –2 –10 
–2x + 5 3 + 20 = 3x 23 3x 3xy = 6 30
–9 + 4x = –5 , 6x + x = y 3x = 6 , –2y = –10
4x = 4 7x = y x = 2 y = 5
x = 1 7(1) = y
y = 7

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