Answer
This system is contradictory and has no solutions.
Work Step by Step
To transform this system to Row-Echelon form we will follows the steps bellow.
Step 1: Subtract from the second equation the first one multiplied by $5$ term by term to eliminate $x$:
$$5x-5x-15y-5\times(-3y) + 10z - 5\times 2 z = 18-5\times 18$$
which becomes
$$0=-72.$$
What we got here in impossible which means that this system is contradictory and has no solutions.
