Question

Factor the equation x^2-3x-18

Answer 1

This is a Non-Perfect Square Trinomial. To factor this type of trinomial, you have to remember this pattern:

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

So you need to find two numbers
`a \ and \ b` such that the product is
`ab` and the middle term is the sum
`(a+b)`. From our polynomial:

`x^2-3x-18`

Those numbers are:

`a=-6 \\ \\ b=3`

Because:

`ab=(-6)(3)=-18 \\ \\ a+b=-6+3=-3`

So:

`\boxed{x^2-3x-18=(x-6)(x+3)}`