How do you factor completely #18m^2-8#?

1 Answer
Oct 28, 2016

Answer:

#18m^2-8 = 2(3m-2)(3m+2)#

Explanation:

The difference of squares identity can be written:

#a^2-b^2 = (a-b)(a+b)#

In our example, we use this with #a=3m# and #b=2# after separating out the common scalar factor #2#, as follows:

#18m^2-8 = 2(9m^2-4)#

#color(white)(18m^2-8) = 2(9m^2-4)#

#color(white)(18m^2-8) = 2((3m)^2-2^2)#

#color(white)(18m^2-8) = 2(3m-2)(3m+2)#