My last two problems

1) x^2 + x − 12 = (x − a)(x − b), determine the value of |a − b|.

2) x^2 − 1 x − 20 = (x − a) (x − b), determine the value of (a − b)^2

for number 2, I did it 4 times and all 4 times I got different answers

I got

81, -81 ,9 ,-9