Check the attached picture, please help me out ! thanks in advance

Solve with work both bert and ernie received an increase in their weekly salaries. bert's salary increased from $520 to $520. ernie's salary went from $580 to $645. find the percent of increase for each salary. what was the larger of the two percents ?

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

Find the missing factor. write your answer inexponential form.9^2=9^4×