Question

Solve the following system of equations.

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

Answer 1

the difference of the first two equations
5y-4z =-5,
y = -1/5 z

Answer 2

the sum of the last two
2x + 2z = -14,

x + z = -7

Answer 3

x=-2
y=3
z=5

Answer 4

Or learn linear algebra, it makes this stuff so much easier!