Algebra
posted by Dorothy on .
Use the elimination method to solve the following system of equations.
x + 3y – z = 2
x – 2y + 3z = 7
x + 2y – 5z = –21

x + 3y – z = 2
x – 2y + 3z = 7

0x +5y 4z = 5
x – 2y + 3z = 7
x + 2y – 5z = –21

0x 4y + 8z = 28 or 2y+4z=14
then
+5y 4z = 5
2y +4z = 14

3 y +0z = 9
y = 3
now go back up and get x and z