Hey there!!
Given :
=> 3x² - 24x + 48
Let's take the common term :-
... 3 ( x² - 8x + 16 )
... 3(x² - 8x + 16)
Let's split the -8x
... 3(x² - 4x - 4x + 16)
... 3(x ( x - 4 ) - 4 ( x - 4 ))
... 3(( x - 4 ) ( x - 4 ))
... 3(x - 4)²
Hence, the answer is 3( x - 4 )²
Hope my answer helps!!