Mmmmmm...... looks lke the first step is incorrect.....
2x - 4y = -6
3x + 2y = -1
6x - 12y = -18 ⇒ Multiplication Property of Equality
-6x - 4y = 2
-16y = -16 ⇒ Addition Property of Equality (with simplification )
y = 1 ⇒ Division Property of Equality
2x - 4(1) = - 6 ⇒ Substitution
2x - 4 = - 6 ⇒ Simplification of previous step
2x = - 2 ⇒ Addition Property of Equality
x = -1 ⇒ Division Property of Equality