Answer:
Reason 4 is wrong in Ethan's solution.
Step-by-step explanation:
Reason 4 is incorrect because at this step in the answer we already have one variable which is unknown on the left side and then one constant which can be seen on the right. So, instead of multiplying the fractions the way Ethan is doing, all you need to do now is just simplify the expression instead of complicating the step.
