Question 120736
If f(x)= 2x + 4, then f(a-4) means to substitute a-4 in place of the x.
f(a-4) = 2(a-4) + 4
f(a-4) = 2a -8 +4
f(a-4) = 2a-4


See my explanation on my website by clicking on my tutor name "rapaljer" anywhere on algebra.com. Click on the first link which is "Basic and Intermediate Algebra", then go to Basic Algebra, Chapter 4, and look for Section 4.09 Functional Notation.


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