These are very difficult and time consuming to do without a calculator but what you have here is (6+x)(6+x)(6+x)(6+x)(6+x)(6+x)
They you have to distribute everything and then combine all like terms. You will end up with 7 terms, 1 for each power of x and 1 whole number
?X^6 + ?X^5 + ?X^4 + ?X^3 + ?X^2 + ?x + ?whole number
The easiest place to start is to distribute the 6 all the way through and you get 6 times 6 times 6 times 6 times 6 times 6 or 6^6 which is 46656
That is your whole number on the end of the expansion
you can also get the first term by distributing the x all the way through x times x times x times x times x times x is x^6
Then it gets a bit harder. Here is the finished expansion so you can work backwards and understand a bit easier hopefully
x^6 + 36x^5 + 540x^4 + 4320x^3 + 19440x^2 + 46656x + 46656