How do you find the product of (3a-4)(3a+4)(3a4)(3a+4)?

1 Answer
Apr 10, 2015

The result is 9a^2 - 169a216

The reason is the following:

The problem is an example of a notable product: "the sum multiplied by the diference is equal to the difference of squares", that is to say: (a+b)·(a-b) = a^2-b^2(a+b)(ab)=a2b2.
By applying this to our question, we obtain that:
(3a-4)·(3a+4) = (3a)^2-(4)^2 = 9a^2 - 16(3a4)(3a+4)=(3a)2(4)2=9a216.