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How Do You Find f(x) If You Have a Value For x?

Given f(x) = 2x-2, find f(-5)

Summary

  1. f(x) is just a notation for a function
  2. It means that our function will be using the variable x
  3. To find f(-5), all we have to do is plug -5 into the function wherever we have an x
  4. Our function is f(x)=2x-2
  5. Plug in -5 for x
  6. 2(-5)=-10
  7. -10-2=-12
  8. So f(-5)=-12

Notes

    1. f(-5) means that we just plug -5 into our function wherever we have an x
    1. f(x) is just a notation for a function
    1. Plugging -5 into 2x-2 gives us f(-5)=2(-5)-2