6+x is an example of an expression. if it was a variable it would be 6x.
Supplementary angles.
This is because supplementary angles are two angles that add up to 180 degrees, and these two angles would add up to 180 degrees.
7z + 10 - z = 8z - 2(z - 5)
7z + 10 - z = 8z - 2z + 10
6z + 10 = 6z + 10
6z - 6z = 10 - 10
0 = 0
Therefore, 7z + 10 - z = 8z - 2(z - 5)
For determining the correct degree of a polynomial, you need to look at each term and find the degree by adding the exponents of each variable in it. The largest degree is the degree of the polynomial.
7x^6 has largest degree of the given polynomial, so your answer is D.6