Since we always want to have an a which equals 1 so then we don't have to do AC method, a longer process, we're going to want to take out the -1.
-1(x^2 - x - 42)
Then, we want to know what two number multiply to equal c (-42 here) and add up to equal b (-1 here). Those two numbers would be -7 and 6 since -7(6) = -42 and -7 + 6= -1.
So then from here we can just plop these numbers into (x+ __).
1(x-7)(x+6)
This is your final answer, A.
