Respuesta :

13(21 - 3a) = 6 - a

273 - 39a = 6 - a

273 (-6) = -1a (+39a)

267/38 = 38a/38

a = 7.02

hope this helps

i'm guessing it's all real numbers?

The correct answer is there are no solutions! so no solution  would be the answer you want to chose