Question

8m^2 - 72n^2

Answer 1

8(m^2 - 9n^2)

Answer 2

textbook says 8(m+3n)(m-3n)

Answer 3

8m^2 - 72n^2 =8(m^2 - 9n^2) = 8(m-3n)m+3n)

Answer 4

taking 8 as a common factor then using the two squares difference rule

Answer 5

Also, this
m^2 - 9n^2

Is a difference of two squares, for which you can use the identity:
a^2-b^2=(a+b)(a-b)

Answer 6

okay. I got the answer i needed, now on the the next...

Answer 7

http://openstudy.com/groups/mathematics/updates/4e7bea180b8b8ad5b6a1ad9c