Respuesta :

ur output value is f(x).....so to do this problem u need to sub in 2/3 for f(x) and solve for the input value which is x

f(x) = -1/3x + 7
2/3 = -1/3x + 7 ...multiply everything by 3
2 = -x + 21
2 - 21 = - x
- 19 = -x
19 = x <== ur output

Answer:

The correct answer is (19).

Step-by-step explanation: