f(4) means that you're substituting x = 4 into the equation for f(x).
So since f(x) = 40x - 20, f(4) = 40(4) - 20 = 160 - 20 = 140.
1 Expert Answer
Still looking for help? Get the right answer, fast.
Ask a question for free
Get a free answer to a quick problem.
Most questions answered within 4 hours.
OR
Find an Online Tutor Now
Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.
