How do u work this problem out

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

Find the percent cost of the total spent on each equipment $36, fees $158, transportation $59 a. 14%, 62%, 23% b. 15%, 60%, 35% c. 10%, 70%, 20% d. 11%, 62%, 27%

5. write an equation for the line that is parallel to the given line and that passes through the given point. y = –5x + 3; (–6, 3)