Question 429511
you are correct for number 2. Let's do problem 1 and then you can use the same process to do 3.

You are given 
{{{A[n] = (1/2)A[n-1] +2}}}  and told {{{A[1]=20}}}
So now find {{{A[2]}}}
Plug in 2 for n in the given forumula
{{{A[2] = (1/2)A[2-1] +2 }}}
{{{A[2] = (1/2)A[1] +2 }}}
Now you see this formula contains {{{A[1]}}} which you know is 20. So subsitute 20 and solve
{{{A[2] = (1/2)20 +2 }}}
{{{A[2] = 10 +2 }}}
{{{A[2] = 12 }}}

Now you have {{{A[2]}}}. So now solve for when n=3
{{{A[3] = (1/2)A[3-1] +2 }}}
{{{A[3] = (1/2)A[2] +2 }}}  you know {{{A[2]}}} because you just solved for it above. Plug 12 in for {{{A[2]}}} and solve for {{{A[3]}}}
{{{A[3] = (1/2)12 +2 }}}
{{{A[3] = 6 +2 }}}
{{{A[3] = 8 }}}
Keep doing this process for n = 4 and then again for n=5.
{{{A[4] = (1/2)8 +2 = 6}}}
{{{A[5] = (1/2)6 +2 = 5}}}

Use the same process for problem 3