If ab - 27 and bc=13 then find the length of ac

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

Question 13 (1 point) jerome is starting a new job. his contract states he will earn $42,000 the first year, and will get a 4% raise per year. which function s(x) represents jerome's salary after a certain number of years, x?

8.74 rounded to the nearest whole number