Answer:
(x+13)(x-1)
Step-by-step explanation:
When factoring x^2+12x-13, you want to think of 2 numbers that add up to 12, using scalar multiples of 13 (so think 13*1=13). We know that 13*1 is the only way to multiply 2 numbers evenly to get to 13, so now, find a combo of 13 and 1 to get 12. This is +13 and -1, so now put them into (x+13)(x-1).