6. An arithmetic sequence has first term \(a\) and common difference \(d\). The sum of the first 10 terms of the sequence is 162 .
- Show that \(10 a + 45 d = 162\)
Given also that the sixth term of the sequence is 17 ,
- write down a second equation in \(a\) and \(d\),
- find the value of \(a\) and the value of \(d\).