Explanation:
this is a college question ? and you don't know how to do that ?
think back to elementary and middle school. and you had to use that all the way through high school as a very, VERY basic skill.
Focus !
g(3) just means that x = 3, and we need to replace every occurrence of x by 3. and then we calculate the result.
g(3) = 4×3 - 5 = 12 - 5 = 7
that's all to it.