Respuesta :

a=11 because 5*2a= 10a and 5*6=30 so now u have 10a+30-a=129. Combine like terms to get 9a. 9a+30=129 subtract 30 from 129 to get 99. Now u have 9a=99. Divide 9 on both sides to get a=11
5(2a+6)-a=129
10a + 30 - a =129
10a - a = 129 - 30
9a = 99
a = 11