I can't add a photo but, put the dot near the -7 point. ( Don't get mad if it's wrong I'm not totally sure to be honest. )
Explain: I doubled the x axis that goes up to 8 so I doubled it by two to get 16 and multiplied 4x4 which equals 16 I subtracted 16 - 16 and got zero after I subtracted 7 and got -7