Question

Tolong jawabin persoalanku

Answer 1

A.
3x + 4y - 5z = 12 (i)
2x + 5y + z = 17 (ii)
6x - 2y + 3z = 17 (iii)

Eliminasi i dengan ii:
3x + 4y - 5z = 12 (i)
2x + 5y + z = 17 (ii)
<=>
6x + 8y - 10z = 24 (i)
6x + 15y + 3z = 51(ii)
<=>
-7y - 13z = -27 (iv)

Eliminasi ii dengan iii:
2x + 5y + z = 17 (ii)
6x - 2y + 3z = 17 (iii)
<=>
6x + 15y + 3z = 51 (ii)
6x - 2y + 3z = 17 (iii)
<=>
17y = 34
y = 2

-7y - 13z = -27 (iv)
-14 - 13z = -27
-13z = -13
z = 1

3x + 4y - 5z = 12 (i)
3x + 8 - 5 = 12
3x = 9
x = 3

x2 + y2 + z2 = 9 + 4 + 1 = 14

B.
x + 2y = -4 (i)
2x + z = 5 (ii)
y - 3z = -6 (iii)

Eliminasi i dengan ii:
x + 2y = -4 (i)
2x + z = 5 (ii)
<=>
2x + 4y = -8 (i)
2x + z = 5 (ii)
<=>
4y - z = -13 (iv)

Eliminasi iii dengan iv:
y - 3z = -6 (iii)
4y - z = -13 (iv)
<=>
4y - 12z = -24 (iii)
4y - z = -13 (iv)
<=>
-11z = -11
z = 1

4y - z = -13 (iv)
4y - 1 = -13
4y = -12
y = -3

2x + z = 5 (ii)
2x + 1 = 5
2x = 4
x = 2

x . y . z = 2 . (-3) . 1 = -6