So the rule with multiplying exponents of the same base is to add the exponents together. Applying this rule here would look like this:

In short, your simplified expression is going to be -16x^7y^6.
F(x)=2x+3
assuming the problem is 4 times 2 minus 2x plus 1
you add like variables
X^2 - 25 is a difference of squares which has a special factorization.
In general, a^2 - b^2 = (a + b)(a - b)
x^2 - 25 = 0
(x + 5)(x - 5) = 0
x + 5 = 0 or x - 5 = 0
x = -5 or x = 5
Steps to solve:
-4z + 4 + 12z = 3z + 4 + 5z
~Combine like terms
8z + 4 = 8z + 4
~Subtract 4 to both sides
8z = 8z
~Divide 8 to both sides
0 = 0
All real numbers are solutions.
Set builder notation: {x | R}
This is an identity since every value can be a solution to the equation.
Best of Luck!