You would do percent of change. meaning you would subract 65 and 50 to get 15. then you would put 15 over 50 (as a fraction) then equals r/100. then you would cross multiply to get r.
For this case, the first thing we must do is define variables. We have then: x: number of blue beads y: number of red beads We now write the inequations system: Answer: a system of linear inequations that represents the situation is: