text: => 2 power x * 2 power (-3) + 2 power x * 2 power (-4) + 2 power x * 2 power (-1) = 11/2+ 11/4 + 11/8 + ...\n\nsn=11/2+11/4+11/8+... --> a1=11/2 , q=1/2   sn=a1/(1-q)\nsn=(11/2)/(1-1/2) ------> sn=11\n2 power x (1/8 + 1/16 + 1/2) = 11\n2 power x = 16\nx=4