Answer:

Step-by-step explanation:
We can use formula (a-b)² = a² -2ab + b².
In our example a = 3c^4 and b = 5c^6
![(3c^{4} - 5c^{6})^{2} = [3c^{4} ]^{2} - 2*3c^{4} *5c^{6} + [5c^{6}]^{2}=\\=9c^{8} -30c^{10} + 25c^{12}](https://tex.z-dn.net/?f=%283c%5E%7B4%7D%20-%205c%5E%7B6%7D%29%5E%7B2%7D%20%3D%20%5B3c%5E%7B4%7D%20%5D%5E%7B2%7D%20-%202%2A3c%5E%7B4%7D%20%2A5c%5E%7B6%7D%20%2B%20%5B5c%5E%7B6%7D%5D%5E%7B2%7D%3D%5C%5C%3D9c%5E%7B8%7D%20-30c%5E%7B10%7D%20%2B%2025c%5E%7B12%7D)
36 divided by 2 = 18 and 18 + 24 = 42
Answer:
C = 12 + 15(x - 4)
C = 15x - 48
Step-by-step explanation:
Let the number of hours = t
The total amount Miguel earns =
C
To edit a manuscript, Miguel charges 12 dollars per hour for the first 4 hours and 15 dollars per hour after the first 4 hours.
C = 12 + 15(x - 4)
Expand the t
C = 12 + 15x - 60
C = 15x - 48
Therefore, an expression for the amount, in dollars, Miguel charges if it takes him t hours to edit a manuscript, where t>4 is given as:
C = 15x - 48
(a²-6)(a²-4) simplify
a⁴-4a²-6a²+24
Combine like terms
a⁴-10a²+24