Question 1: Consider (1+x^2+x^3)^n,where n is a positive integer. a) Find the coefficients of x^5 and x^7 in terms of n. b) If the ratio of the coefficient of x^7 to that of x^5 is 5:1, find the value of n. Question 2: a)Expand (1+x-2ax^2)^n,where n is a positive integer,in ascending powers of x up to the term x^2. b) If the cofficient of x and x^2 are 7 and 0 respectively, find the values of n and a._________________

1+1= 2 or 1+1=11 (rejected)