Решение неравенства : 2^x + 2^x+3 < 9

[latex]2^x+2^{x+3} extless 9\\2^x(1+2^3) extless 9\\2^x(1+8) extless 9\\2^x*9 extless 9 |:9\\2^x extless 1\\2^x extless 2^0\\2 extgreater 1\\x extless 0\\xin(-infty;0)[/latex]