tolong ya di jawab no 11-15 dengan caranya .soalnya besok akan di kumpulkan

11. f ( 5) = 5^2 - 5n = 10
= 25 - 5n = 10
= 25 - 10 = 5n
= 15 = 5n
= 3 = n
13. b
14. y2-y1/x2-x1 = 3-4/-2-2 = -1/-4 = 1/4
15. -a/b = -4/-2 = 2