Answer:
Part 1: 5
Part 2:

Part 3:

Part 4:9(2s-7)
Part 5:

Part 6:

Part 7:

Explanation:
Part 1: we have to find the degree of monomial

The degree of a polynomial is the highest degree of its monomials (individual terms) with non-zero coefficients.
The degree of monomial= 3+2=5
Option c is correct.
Part 2: simplify




Option b is correct.
Part 3: simplify


By distributive property

Option a is correct.
Part 4: . factor 18s-63
18s-63
Taking 9 common from both terms
9(2s-7)
Option d is correct.
Part 5: simpler form of



Option d is correct.
Part 6: simplify (x+7)(x+5)

Option a is correct.
Part 7: simplify



Option d is correct.