F (x) = - 1/3 x + 7 determine the input that would give an output value of 2/3

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