Answer:
12
Step-by-step explanation:
The problem statement tells us the definition of 3f(x). In order to find the value of 3f(2), we substitute 2 for x and do the arithmetic.
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definition
3f(x) = 3x² . . . . given
application
3f(2) = 3·2² = 3·4 = 12 . . . . . substitute 2 for x
The value of 3f(2) is 12.
