How to solve this algebra II problem (solving systems of linear equations in 3 variables)?

Which values should be given to a, b, and c so that the linear system shown has (-1, 2, -3) as its only solution?

x + 2y - 3z = a
- x - y + z = b
2x + 3y - 2z = c

thanks in advance! ♥
3 answers 3