normally, we could add exponents.
however, that only is possible when the bases are the same
recall what exponents mean
12³=12*12*12
so we cannot add exponents for 12³*11³ because that means 12*12*12*11*11*11
it would not equal 12⁶ or 11⁶
or you could refer to the rule
notice when x=x then we can add the bases
fun fact below
we can reverse a previous exponential rule like this
since
then
therefor
we can't add the exponents because the bases are not the same