Answer:
$11111.11
Explanation:
His salary is computed as ...
... 1000 + 0.09·sales
He wants this to be 2000, so we can write ...
... 2000 = 1000 + 0.09·sales
... 1000 = 0.09·sales . . . . . . . . . subtract 1000
... 1000/0.09 = sales . . . . . . . . . divide by the coefficient of sales
... 11,111.11 = sales