What is the value of AAA when we rewrite \left(\dfrac{2}{3}\right)^{x+4}-\le ft(\dfrac{2}{3}\right)^{x}( 3 2 ) x+4 −( 3 2 ) x left parenthesis, start fraction, 2, divided by, 3, end fraction, right parenthesis, start superscript, x, plus, 4, end superscript, minus, left parenthesis, start fraction, 2, divided by, 3, end fraction, right parenthesis, start superscript, x, end superscript as A\cdot \left(\dfrac{2}{3}\right)^{x}A⋅( 3 2 ) x A, dot, left parenthesis, start fraction, 2, divided by, 3, end fraction, right parenthesis, start superscript, x, end superscript ?