Answer:
x=1
Explanation:
I'm not completely sure I'm correct but if 12 and 13x-1 are equal, then try different numbers for x until you find the number that makes 13x-1 equal 12. For example: If x=0, 13(0)-1 equals -1.
if x=1, 13(1)-1 equals 12.
Therefore, x is 1.