Each input should only have 1 output. Multiple inputs can have the same output, but one input can only correspond to a single output.
Also, if you graph the relation with the input as the x coordinate and output as the y coordinate, you can then conduct a verical line test. Anywhere you draw a vertical line, you should only intersect the curve one time.
according to the pictures I have sent you can solve it! be successful
A. 25 = (.5 * 22) + (2 * x)
B. 25 = (.5 * 22) + (2 * x)
25 = 11 + 2x
14 = 2x
7 = x
C. 7