Question

For the following exercise, evaluate the expressions, given functions f and g :• f(x) = 3x - 2• g(x) = 5 – x274. 3f(1) - 4g(-2)

Answer 1

Answer: 3f(1) - 4g(-2) = 2

Explanation:

To evaluate the expression we need to find first f(1) and g(-2)

So, f(1) is calculated replacing x by 1 in the function f(x), then:

$\begin{gathered} f(x)=3x-2 \\ f(1)=3\cdot1-1 \\ f(1)=3-1 \\ f(1)=2 \end{gathered}$

At the same way, g(-2) is calculated as:

$\begin{gathered} g(x)=5-x^2 \\ g(-2)=5-(-2)^2 \\ g(-2)=5-4 \\ g(-2)=1 \end{gathered}$

Finally, 3f(1) - 4g(-2) is equal to:

$\begin{gathered} 3f(1)-4g(-2) \\ 3\cdot2-4\cdot1 \\ 6-4 \\ 2 \end{gathered}$

Therfore, 3f(1) - 4g(-2) is equal to 2