Question

How do you factor the expression `x^2 + 3x + 2`?

Answer 1

`x^2+3x+2 = (x+1)(x+2)`

Explanation:

Note that in general:

`(x+a)(x+b) = x^2+(a+b)x+ab`

So can we think of two numbers `a, b` such that `a+b=3` and `ab = 2` ? How about `1` and `2` ?

So:

`x^2+3x+2 = (x+1)(x+2)`