Question

Medal
Solve by determinants.
x + y + z = 21
x=y +z = 3
x +y - z = 1

Answer 1

is there a typo in the second equation `x=y +z = 3` ??

Answer 2

there are 2 equal signs there

Answer 3

yes sorry its x - y + z = 3

Answer 4

ok thanks

Answer 5

were you able to set up the matrix?

Answer 6

yes

Answer 7

what matrix did you get

Answer 8

1 1 1
1 -1 1
1 1 -1

Answer 9

m i right?

Answer 10

good

Answer 11

that's your coefficient matrix

Answer 12

do you know how to take the determinant of that matrix?

Answer 13

no

Answer 14

focus on the first two columns