I've Answered a question like this in the past (though it was linear) examples of a linear table are x:1234
and then y: -3 -5 -7 -9. so for a non linear table it would have to be odd numbers x:1234
y:3 6 12 24
remember my example and dont use 1234, -3 -5 -7 -9 ok?
Subtitute the pair (3,28) to x and y, if the result in right side is -8, then the pair is a solution to the equation
2x - y/2
= 2(3) - 28/2
= 6 - 14
= -8
The result is -8, so the pair (3,28) is a solution