The table shows the outputs, y, for different inputs, x: input (x) 3 , 4 , 5 , 6 output (y)3 , 4 , 5 , 6 what is the value of x if f(x) = 40? (20 points)

It seems like there's a typo? The x and y rows are identical

Assuming there is no typo, then the input and the output are the same. Meaning that whatever you plug in, is what comes out. If the output is 40, then the input must be 40. 

So the answer is 40 (assuming there are no typos made by your textbook or teacher)

1200 inches = 30 yards12 inches= 1 foot3 feet= 1 yard3feet= 36 inchesyou can set up a proportion then use inverse operations that looks sorry it looks so sloppy lol