A.) Simplifying the equation would lead you to 15x^2-3x+9
b.) You know your answer is correct because you're adding the two polynomials together. 9x^2+6x^2 is 1tx^2. Now you have 2x-5x and since the negative is bigger, you get -3x. Then 5+4 is 9. You have no like terms therefore your answer is 15x^2-3x+9
The change of base formula allows you to write a logarithm in terms of logarithms with another base. It follows this pattern,

where a≠1 and b≠1
Assigning the base to be 7,

I hope I was able to answer your question. Have a good day.
I’m sorry but I really have no idea I wish I could help
None of the above I believe
Where are the following grades ? how am i supposed to answer without all parts of the question .