Using the splitting middle term - the middle term of the general equation is divided in two such values that:

Product = a.c

For the given equation a = 3; b = -2; c = -1

= 3. - 1 = - 3

And either of their sum or difference = b

= - 2

Thus the two terms are - 3 and 1

Difference = - 3 + 1 = - 2

Product = - 3.1 = - 3

3x(x-1) + 1(x-1) = 0

(x-1)(3x + 1) = 0

(x-1) = 0 or (3x + 1) = 0

x = 1 or x = (-1)/3

Roots of equation are 1, (-1)/3