Let's analyze each step.
Step 1 to Step 2: here, Irene used the distributive property of multiplication to get rid of the parenthesis. She have done this correctly, with the sign and everythig - ok
Step 2 to Step 3: now, she added "-18" and "+10" with the correct result of "-8" - ok
Step 3 to Step 4: Next, she added "8" to both sides, which cancels the "-8" in the left side and add "8" to "-2", ending with 6, this is correct - ok
Step 4 to Step 5: Here, she divides both sides by "-6". The intention is correct, but when we divide both sides by a negative value in an inequality, we need to change the direction of the inequality sign. So, the Step 5 should have been:
Thus, the mistake is made from step 4 to step 5, fourth alternative.