Answer:
Part a) 
Part b) 
Part c) 
Part d) 
Step-by-step explanation:
Part a) The difference of the squares of 2m and 7n.
we know that
The difference of the squares formula is equal to

substitute

Part b) The square of the difference of x and 8y
The formula of the square of the difference between two numbers is equal to

substitute

Part c) The tripled product of 6a and b^2
we have

Part d) The product of the sum of a and b and their difference
The expression is equal to

The expression represent the difference of the squares between a and b
so
