## College Algebra (6th Edition)

The statement $(3x^3+2)(3x^3-2)=9x^9-4$ is false. The correct statement is $(3x^3+2)(3x^3-2)=9x^6-4$.
The product of the sum and difference of two terms can be found using the formula $(a+b)(a-b)=a^2-b^2$. $$(3x^3+2)(3x^3-2)=(3x^3)^2-2^2$$ To raise an exponent to an exponent, multiply the exponents: $$=9x^{(3\times 2)}-4$$ $$=9x^6-4$$