Mohon bantuannya kakak kakak

Berarti :

z = 4(2) + (-1).5 = 8-5 = 3

x -3y = -13 –> 2x-6y = -26

2x +5y = -4–> 2x+5y = -4

———————————- –

-11y = -22

y = 2

x = -13+3(2) = -13+6 = -7

x -y -z = -7 -2 – 3 = -12