How do you factor completely 3x^2 - 9x - 30?

1 Answer
Apr 29, 2018

Divide the whole equation by 3 to simplify:

3x^2-9x-30=x^2-3x-10

Find factors of 10 : 1,2,5,10):
2 and 5 work to make 10 and 3

Therefore,

(x+2)(x-5)

Do not forget to add the three back!

3((x+2)(x-5))

So you would multiply out the brackets first, then the result should be x^2-3x-10. Multiply all factors out with 3 and this should give you 3x^2-9x-30