Simplify each of the products: `(1/2a-3b)(1/2a+3b)(1/4a^2+9b^2)`

Explanation

we can write it as
`(1/2a-3b)(1/2a+3b)(1/4a^2+9b^2)`
as we know,
`(a+b)(a-b)=a^2-b^2`
so,
`(1/2a-3b)(1/2a+3b)(1/4a^2+9b^2)`
`=(1/4a^2-9b^2)(1/4a^2+9b^2)`
again using
`(a+b)(a-b)=a^2-b^2`
we get,
`(1/4a^2-9b^2)(1/4a^2+9b^2)=(1/16a^4-81b^4)`