Urgent notice

1).if f(x) = x+1,.g(x) = x^2+1 fog (-2) =?

ans: 6.

2).if f(x-1) = x^2-4x+8 then f(x+1) = ?

ans : x^2+4

3).the value of 2logx+2logx^2+2logx^3 -----------------------nlogx^n =

ans: n(n+1)logx.

4).the recurring decimal 2.777 -----------is expressed as

ans: 25/9.

5).one root of x^2-3x+k = 0 is 2 then k is

ans: 2.

6).the value of k for which the roots of the equation 12x^2+kx+5 = 0 in the ratio 3:2.

ans: 5.10^1/2.