Question

Can someone please explain how it goes from 0=x^2-2x-3 to 0=(x+1)(x-3)

Answer 1

Basically you are trying to find two numbers that when they are added equals -2 and when multiplied equals -3. As you can see -3 plus +1 is equal to -2. And 1 times -3 equals -3. Therefore you have (x+1)(x-3). In order to check if these are the right numbers you will need to multiply (x+1)(x-3) and will end up with the first equation x^2-2x-3. Hope this helped! :)