Answer:
[tex]-39x-31[/tex]
Step-by-step explanation:
[tex]\text{First term,}~ a = x+9\\\\\text{Common difference,}~ d = -3x+5 -x -9 = -4x-4\\\\\text{nth term,}~ a_n = a + (n-1) d\\\\~~~~~~~~~~~~~~~~~~=x+9+(n-1)(-4x-4)\\\\~~~~~~~~~~~~~~~~~~=x+9-4nx+4x-4n+4\\\\~~~~~~~~~~~~~~~~~~=5x-4nx-4n+13\\\\\text{11th term}~ a_{11} = 5x-4(11)x -4(11) + 13\\\\~~~~~~~~~~~~~~~~~~~=5x-44x-44+13\\\\~~~~~~~~~~~~~~~~~~~=-39x-31[/tex]
