Answer:
f(12) = 90
Explanation:
This is more of a notation problem than anything else.
The x on the left means that the variable is x. That sounds weird I know, but it starts out this way.
f(variable) = 8*variable - 6
Where you see the word variable, you put the letter x and that gives you the question.
f(x) = 8*x - 6
That is math shorthand for whatever you see on the left, like an x or in this case 12, you put the value 12 in for x on the right. It will look like this.
f(12) = 8*12 - 6 Now it just becomes a calculator problem.
f(12) = 96 - 6
f(12) = 90