(2) If the taxpayer's monthly salary is X yuan, then

When x is less than or equal to x≤5000, it is obvious that the tax amount is less than 8% of the monthly salary.

When 5000 < x ≤ 9000, it is changed from1500× 3%+(x-5000 )×10% > 8% X.

X > 22750, which does not meet the requirements;

When 9000 < x ≤ 1 1000, the ratio of1500× 3%+3000×10%+(x-9000 )× 20% > 8% x,

The solution is x > 10459, so 10459 < x ≤ 12000 is ok.