That is fine as long as we remember to factorize the product of a and c, that is the constant term and the coefficient of x square such that their sum is equal to b, coefficient of x. For example let us factorize
3x^2 - 5 x - 2 = 0; a = 3, b = -5, c= - 2;
Product of a and c = - 6
factors of 6; - 6 x 1 = - 6 sum of factors = - 6 + 1 = - 5
Now split the middle term
3x^2 - 6x + x - 2 = 0 Now you can proceed further