I need help with this As I am new to this subject/branch of mathematics, please explain and clarify step-by-step on how to complete this practice

solution:
We want to find the equivalent expression to the expression;
[tex](3x-4y^2)(3x+4y^2)[/tex]Using the difference of 2 squares formula, which is;
[tex](a-b)(a+b)=a^2-b^2[/tex]We can do the same for the given expression, so we can write;
[tex](3x-4y^2)(3x+4y^2)=(3x)^2-(4y^2)^2[/tex]This is equivalent to;
[tex](3x)^2-(4y^2)^2=9x^2-16y^4[/tex]Thus, the final answer is ;
[tex]9x^2-16y^4[/tex]