SOLUTION: Given g(x) = 5x � 2, find g(3a). HELP I have no idea how to do this problem and no one else seems to be able to tell me how to do it either. Can someone help please?

Question 103093: Given g(x) = 5x � 2, find g(3a).
HELP I have no idea how to do this problem and no one else seems to be able to tell me how to do it either. Can someone help please?
Answer by oberobic(2304) (Show Source): You can put this solution on YOUR website!
The idea here is to substitute the new value into the function.
Usually, f(x) is the function, but this time it is g(x).
We are told, g(x) = 5x - 2.
That is the function. Think of it like a machine that takes some input and multiplies it by 5 and then subtracts 2: Input x and out comes 5x-2.
Here were are told to find g(3a), so they are telling us that x=3a. Simply substitute: Plug in 3a to the "function machine" and out comes 5 times 3a - 2:
g(3a) = 5(3a) - 2
g(3a) = 15a - 2

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