Given W^2-W-12 = w^2+bW+c b=-1, c=-12 We look for m, n so that m+n=b=-1, m*n=c=-12, where m,n are integer factors of -12.
Now enumerate all possibilities for m*n=12 m n m*n m+n 1 -12 -12 -11 2 -6 -12 -4 3 -4 -12 -1 ....... so m*n=-12, m+n=-1 The factorization is then W^2-W-12=(W+3)(W-4)
