# How do you factor completely #25a^4-49b^2#?

##### 1 Answer

Apr 19, 2017

#### Answer:

#### Explanation:

Note that both

The difference of squares identity can be written:

#A^2-B^2=(A-B)(A+B)#

Using this with

#25a^4-49b^2 = (5a^2)^2-(7b)^2#

#color(white)(25a^4-49b^2) = (5a^2-7b)(5a^2+7b)#

There are no simpler factors.