2a if a = 3 how do I get the answer

Pick the expression that matches this description: a polynomial of the 5th degree with a leading coefficient of 7 and a constant term of 6 (choice a) 7x^5+2x^2+6 (choice b) 7x^6−6x^4+5 (choice c) 6x^7−x^5+5 (choice d) 6x^5+x^4+7

God's gym charges a sign-up fee of $100 plus $30 per month. write an expression to represent how much someone would pay for a membership.

Determine the required value of the missing probability to make the distribution a discrete probability distribution. x p(x) 3 0.23 4 ? 5 0.51 6 0.08 p(4) = nothing  (type an integer or a decimal.)