Question

How do you factor 9x^2 - 30x + 25?

Answer 1

The easiest way (in my opinon) is putting it into the form:
`a(x+b)^2+c`

This would take the form from `ax^2+bx+c`

By putting 9 outside the brackets you can say:
`9(x^2-30/9 x)+25`

Then to get the b you divide `-30/9` by 2 to get `-30/18=-5/3`
so you get
`9(x-5/3)^2+c`
To get `c` you need to expand out the `5/3` to get `9(-5/3)^2`
`9(-5/3)^2=25`
then `c = 25`(actual value)`- 25`(expanded value)

Then you can put the whole equation in making the answer:
`9(x^2-5/3)^2`