If y=14 when x=8 determine the value of y when x = 12

With this information there could be several answers.

14 = 8 + 6 so the equation could be y=x+6, which would give us 18.

But also, 14 = 8/2 + 10, so the equation could also be y = x/2+10, which would give us 16.

You could get several answers