Hi, need help with this, which area model would be correct?

Me with this one question, and i'll upvote the brainliest answer

Jordan has $5.37, which he is using to buy ingredients to make salsa. he is buying one red pepper for $1.29 and three pounds of tomatoes. if jordan has exactly the right amount of money he needs, what is the price per pound of the tomatoes? choose the correct equation to represent this real-world problem. solve the equation and verify the reasonableness of your answer. a pound of tomatoes costs .

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?