Elementary Row Operations: Perform the elementary row operations on the given system of equations and write the resulting system. (Mathematics)
x + y - z = 8 (Eq1)
2x - y + 3z = 9 (Eq2)
x + 2y + z = 5 (Eq3)
***(Eq1) <> (Eq2)
a) x + y - z = 8
b) x + 2y + z = 5
c) x - y + 3z = 9
d) 2x - y + 3z = 9