Nilai z yang memenuhi persamaan : x(2,5,2) + y(-1,-6,5) = (-7,-21,2z-21) adalah

Nilai z yang memenuhi persamaan : x(2, 5, 2) + y(-1, -6, 5) = (-7, -21, 2z - 21) adalah ....  

Pembahasan :  

x(2, 5, 2) + y(–1, –6, 5) = (–7, –21, 2z – 21)
(2x, 5x, 2x) + (–y, –6y, 5y) = (–7, –21, 2z – 21)
(2x – y, 5x – 6y, 2x + 5y) = (–7, –21, 2z – 21)  

2x – y = –7 |x 6|
5x – 6y = –21 |x 1|  

12x – 6y = –42
5x – 6y = –21
------------------ -
7x = –21
x = –3  

2x – y = –7
2(–3) – y = –7
–6 – y = –7
–y = –1
y = 1  

2x + 5y = 2z – 21
2(–3) + 5(1) = 2z – 21
–6 + 5 + 2z = –21
–1 + 2z = –21
2z = –21 + 1
2z = –20
z = –10
 
=============================================

Kelas : 12 KTSP
Mapel : Matematika
Kategori : Vektor
Kata Kunci : Kesamaan Vektor
Kode : 12.2.4 (Kelas 12 Matematika Bab 4 - Vektor)