1.Given that and , calculate

(a)

(b)

I got (a) right to be 8-6x^2. (b) however I got wrong. I got 36x^2+24x+3. What did i do wrong here?

2.How many ways are there to select 11 countries in the United Nations to serve on a council if 2 is selected from a block of 51, 2 are selected from a block of 67 and 7 are selected from the remaining 71 countries?

I got 710, but that's incorrect.