What is the formula for factorization

(a + b) (c + d), ac + ad + bc + bd, 2x squared + x - 3 or (2x + 3) (x - 1).

Step-by-step explanation:

For an expression of the form (a + b) (c + d), the expanded version is ac + ad + bc + bd, in other words everything in the first bracket should be multiplied by everything in the second. Factorising is the reverse of expanding brackets, so it is, for example, putting 2x² + x - 3 into the form (2x + 3) (x - 1).

Multiply the coefficient of x^2 in the original