Answer:
see explanation
Explanation:
to evaluate f(a) substitute x = a into f(x)
f(a) = 5a + 4
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2f(a) = 2(5a + 4) = 10a + 8
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to evaluate f(2a) substitute x = 2a into f(x)
5(a + 2) + 4 = 5a + 10 + 4 = 5a + 14
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f(a) + f(2) ← substitute x = 2 into f(x)
= 5a + 4 + 5(2) + 4 = 5a + 4 + 10 + 4 = 5a + 18