A + 2B = 22b + 3C = 3C + 3A = 7, find the solution of a + B + C

A + 2B = 22b + 3C = 3C + 3A = 7, find the solution of a + B + C

Add the left and right sides of the three formulas
4a+4b+4c=12
a+b+c=3