Since it's multiplied to the power of two, you are multiplying (7x-6) to itself
So you have (7x-6)(7x-6)
Multiply the 7x out so you have:
49x^2 - 42x
Now do the same to the -6 so you have:
-42x + 36
49x^2 - 42x - 42x + 36
Combine like terms, and your final answer is:
49x^2 - 84x + 36
