Answer: a²-5a+4
Explanation:
When brackets are next to each other in algebra it means to multiply.
So,
a×a=a²
a×-1=-a (in algebra, you don't write -1a you would just write -a)
-4×a=-4a
-4×-1=+4
So then you would write it like this:
a²-a-4a+4
Then you would simplify it:
a²-5a+4
Hope this helps :)