Taxes and states

[Precept]

Hi, we are planning to open a new Office in Texas. We currently have activities in Florida and I would like to know how it works for state tax.

Let's say I have 80% of my business income from Florida and 20% from Texas, will I calculate my taxes on business multiplied by 80 % for Florida and 20 % for Texas ?

And is there any special taxes in Texas I should be aware of ?

Thanks.