Twice the sum of a number and 3 is equal to three times the difference of the number and 3

Twice the sum of a number and 3 = 2(n + 3)
three times the difference of the number and 3 = 3(n - 3)
so
Twice the sum of a number and 3 is equal to three times the difference of the number and 3:
2(n + 3) = 3(n - 3)
2n + 6 = 3n - 9
n = 15

answer
2(n + 3) = 3(n - 3)
n = 15

No a triangle cannot be formed because when you add the two smallest number together (which would be 11) the have to be bigger than the number it is "against" ( which would be 12)