Question

4. ( 6x²y + 3ab)(6x²y -3ab) = ( _____ ) - 9a²b²

Answer 1

The answer is;

36x^4y^2 - 9a^2b^2

Explanation:

Here, we simply want to write the right hand side in the form of the left hand side.

The best route to use here is the route of the difference of two squares.

Say we have the value a^2-b^2

We can simply write this as (a-b)(a + b)

This looks similar to what we have in the question above. What is left is just to

multiply the term 6x^y together and place it before the subtraction sign.

Mathematically;

6x^2y * 6x^2y = 36x^4y^2