Answer:
f(4) = 8
f(6) = 10
Step-by-step explanation:
Step 1: Define
f(x) = x + 4
f(4) is x = 4
f(x) = 10
Step 2: Find f(4)
f(4) = 4 + 4
Step 3: Find f(x) = 10
10 = x + 4
x = 6
