Answer:
The value of x ix $18400.
Step-by-step explanation:
Any amounts earned up to $x are free from income tax.
Any amounts earned beyond $x are taxed at 25%.
Tammy earns $40,000 gross annual salary and pays $5,400 per annum in income tax.
We can calculate as following; Assuming x < 40000
=>
=>
x = 18400
Hence, the value of x ix $18400.