Solve for a : C + 3a = 7
C + 3a= 7C-C+3a= 7-C3a= 7-C3a/3= (7-C)/3a= (7-C)/3
a= 7 - C 3 C+3a=7 -C -C 3a = 7-C 3 3 A = 7 - C 3