If 4^a +4^a+1 = 4^a+2 - 176 , what is the value of a?

here is what im confused about with the solution provided.

For the right side of the equation, after simplifying we get one part as -4^a - 4^a . Understood, but then this further turns into 4^0

How did it get to 4^0??

if we take 4^a as common, then should leave 1-1 which is 0 which then multiplies by 4^0 to give us ZERO. But in the solution, it is 1.