u/Euphoric-Pie-4372

I am an A-Level student and i've been finding these type of problems rly hard. I want a straightforward method that doesnt involve me having to imagine how the molecule would look like if i rotated it. That is way too confusing for me and not possible in a time crunch. Also i would like to preferably not have to learn any new, complex concept or rules for such questions, but if no alternative, im fine with that as well.
I know that the main objective in the first question is to find a pair of enantiomers as they would form a racemic mixture and thus be optically inactive, but identifying the enantiomers itself is what im finding hard. Similar problem with the second question as well.
Thanks!