Those are perfectly legitimate costs of business, and would be deductible. How you deduct them is the key.
I can't speak to the ins and outs of LLC's and partnership income taxes, but if your income is via a 1099 and you're using Schedule C, you simply deduct them along with your other business expenses. You're only taxed on the net profit after expenses, not the gross income beforehand. Your expenses are taken right off the top. If you have $100,000 in 1099 income and $5,000 in business expenses, your profit (taxable income) is now down to $95,000.
Trying to deduct them if you're a W-2 employee only is the least desirable. Your business-related expenses in that case are deductible, but only to the extent they exceed more than 2% of your adjustable gross income. So let's say you have an AGI of $100,000, and $5,000 in business expenses. 2% of your AGI is $2,000, so that means only $3000 of it is deductible AND it's taken on Schedule B along with your other itemized deductions. Even worse, if you didn't have enough itemized deductions to even exceed the standard deduction, those business expenses might end up not really being deductible at all.
I'm lucky enough to have both 1099 income from moonlighting along with my W2 income from my regular employer. That means that any of my employment related expenses (licensing, certification, education meetings and associated travel and meals, etc.) are all deductible right off the top of my 1099 income. If I only make $2000 in 1099 income, and have $5000 in expenses, I can legitimately show a $3000 loss, which reduces my AGI. It's one of the biggest perks of having 1099 income sources instead of all W-2.