Answer:
x = 20
Step-by-step explanation:
By exterior angle theorem, we have:

3x-12y = 5
-x+3y = 9
First step is to make the coefficient of either x or y same.
3x-12y = 5
(-x+3y = 9)3
3x-12y = 5
-3x+9y = 27
-4y = 32
y = -8
Prime because u can not times anything besides 1 and itself there fore it is a prime number
4 less than 8 is a number N
8 - 4 = n
or
n = 8 - 4