2 ^ x * 2 ^ ( x + 4 ) = 2 ^ ( x + x + 4 ) = 2 ^ ( 2x + 4 )
16 * 2 ^ ( x - 3 ) = ( 2 ^4 ) * 2 ^ ( x - 3 ) = 2 ^ ( x + 1 )
2 ^ x * 2 ^ ( x + 1 ) = 2 ^ ( 2x + 1 )
2 ^ ( 2x + 4 ) - 2 ^ ( 2x + 1 ) = 2 ^ ( 2x + 1 ) * ( 2^3 - 1 ) = 2 ^ ( 2x + 1 ) * 7
Ответ 7 * ( 2 ^ ( 2x + 1 ))