Matrices - Linear algebra (application problem)

[halcyon aspen]

substitution Z for X

[tender gate]

substitution should work

z = 4x

so 5x +y = 15000

10x/20+4y/20 = 5z/20

so then you get 10x+4y = 5z

4y = 10x

with substitution

then divide by 2

2y = 5x

then replace 5x in first equation with 2y

to get 3y = 15000

therefore y = 5000

therefore 10,000 = 5x

so x = 2000

therfore z = 8000

so your answers are correct, good job!