Question

F(x)= { 7 if 12<or=x<or=13 8 if 12<or=x<or=13 } ?????????

Answer 1

Looking at the actual structure of your question you have written:
`F(x)=7 if 12<=x<=13`
`F(x)=8 if 12<=x<=13`
`color(red)("This is a contradiction. Is one of the lines wrong?")`