In the expansion of x^7 (x^4/2 + k/x^3)^7, the constant term is 168. Find the value of k.

(if f(x)=4x^2 and g(x)=x+1, find (f o g)(x)

5500 dollars is placed in an account with an annual interest rate of 6.5%. to the nearest tenth of a year, how long will it take for the account value to reach 19700 dollars?

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)