Here are the steps in finding the difference of the given polynomial.
1. Simplify the first term by multiplying 3n² by the terms inside the parenthesis.
2. Eliminate the parenthesis on the second term by multiplying the negative symbol by the terms inside the parenthesis.
3. Arrange the terms according to their exponents or degree.
4. Combine similar terms. Similar terms are terms with the same variable and with the same exponent like 3n⁴ and n⁴.
Hence, the difference between the given polynomial is 4n⁴ + 12n³ - 17n² - 3 as shown above.
The degree of the polynomial is 4.
There are 4 terms in the polynomial.