Answer:
[tex]9 + n[/tex]
Step-by-step explanation:
Well it's an arythmetic sequence, so it will look like:
[tex]a + d\cdot n[/tex]
Note that the first element is:
[tex]a + d\cdot 1[/tex]
and the second element is:
[tex]a + d \cdot 2[/tex]
So the difference between the two gives us d!
[tex]d = 11 - 10 = 1[/tex]
Now let's find the [tex]a[/tex]:
[tex]a + d\cdot 1 = 10\\a + 1 \cdot 1 = 10\\a + 1 = 10\\a = 9[/tex]