If a is a positive integer, then 2^a + 2^(a + 1) + 2^(a + 2)= Choose the most appropriate option:  A) 3^(a + 1)  B) 2^(a + 1)  C) 2a  D) 2a^(a + 1)  E) 7(2^a)
If a is a positive integer, then 2^a + 2^(a + 1) =   2^a + 2^(a + 1)+2^(a + 2)   2^a(1+2+4)   2^a(7)   E. 7(2^a)
<result>E</result>
If a is a positive integer, then 2^a + 2^(a + 1) + 2^(a + 2)=