PLs help

Which expression will have the same sum as 3_8 + 1/4?

Find the value of p for which the polynomial 3x^3 -x^2 + px +1 is exactly divisible by x-1, hence factorise the polynomial

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)