Given the inequality:
$$- 2 \cdot 9^{x} + \left(6 \cdot 4^{x} + 6^{x}\right) \geq 0$$
To solve this inequality, we must first solve the corresponding equation:
$$- 2 \cdot 9^{x} + \left(6 \cdot 4^{x} + 6^{x}\right) = 0$$
Solve:
$$x_{1} = -103.016148295613$$
$$x_{2} = -45.0161475312093$$
$$x_{3} = -39.0161395897739$$
$$x_{4} = -29.0156505597641$$
$$x_{5} = -97.0161482956131$$
$$x_{6} = -47.0161479558756$$
$$x_{7} = -23.0109910424438$$
$$x_{8} = -71.0161482955929$$
$$x_{9} = -35.0161042493011$$
$$x_{10} = -55.016148282357$$
$$x_{11} = -57.0161482897215$$
$$x_{12} = -75.0161482956091$$
$$x_{13} = -61.0161482944493$$
$$x_{14} = -49.0161481446181$$
$$x_{15} = -65.0161482953832$$
$$x_{16} = -113.016148295613$$
$$x_{17} = -33.0160492860239$$
$$x_{18} = -95.0161482956131$$
$$x_{19} = -101.016148295613$$
$$x_{20} = -87.016148295613$$
$$x_{21} = -109.016148295613$$
$$x_{22} = -69.0161482955677$$
$$x_{23} = -25.0137179041395$$
$$x_{24} = -83.0161482956129$$
$$x_{25} = -41.0161444260271$$
$$x_{26} = -63.0161482950958$$
$$x_{27} = -91.0161482956131$$
$$x_{28} = -93.0161482956131$$
$$x_{29} = -51.0161482285041$$
$$x_{30} = -89.0161482956131$$
$$x_{31} = -105.016148295613$$
$$x_{32} = -73.0161482956041$$
$$x_{33} = -27.0150406393294$$
$$x_{34} = -107.016148295613$$
$$x_{35} = -43.016146575733$$
$$x_{36} = -111.016148295613$$
$$x_{37} = -31.01592600289$$
$$x_{38} = -99.0161482956131$$
$$x_{39} = -53.0161482657869$$
$$x_{40} = -115.016148295613$$
$$x_{41} = -81.0161482956127$$
$$x_{42} = -85.016148295613$$
$$x_{43} = -37.0161287111672$$
$$x_{44} = -67.0161482955109$$
$$x_{45} = -79.0161482956123$$
$$x_{46} = -77.0161482956113$$
$$x_{47} = -59.0161482929946$$
$$x_{48} = 1.70951129135145$$
$$x_{1} = -103.016148295613$$
$$x_{2} = -45.0161475312093$$
$$x_{3} = -39.0161395897739$$
$$x_{4} = -29.0156505597641$$
$$x_{5} = -97.0161482956131$$
$$x_{6} = -47.0161479558756$$
$$x_{7} = -23.0109910424438$$
$$x_{8} = -71.0161482955929$$
$$x_{9} = -35.0161042493011$$
$$x_{10} = -55.016148282357$$
$$x_{11} = -57.0161482897215$$
$$x_{12} = -75.0161482956091$$
$$x_{13} = -61.0161482944493$$
$$x_{14} = -49.0161481446181$$
$$x_{15} = -65.0161482953832$$
$$x_{16} = -113.016148295613$$
$$x_{17} = -33.0160492860239$$
$$x_{18} = -95.0161482956131$$
$$x_{19} = -101.016148295613$$
$$x_{20} = -87.016148295613$$
$$x_{21} = -109.016148295613$$
$$x_{22} = -69.0161482955677$$
$$x_{23} = -25.0137179041395$$
$$x_{24} = -83.0161482956129$$
$$x_{25} = -41.0161444260271$$
$$x_{26} = -63.0161482950958$$
$$x_{27} = -91.0161482956131$$
$$x_{28} = -93.0161482956131$$
$$x_{29} = -51.0161482285041$$
$$x_{30} = -89.0161482956131$$
$$x_{31} = -105.016148295613$$
$$x_{32} = -73.0161482956041$$
$$x_{33} = -27.0150406393294$$
$$x_{34} = -107.016148295613$$
$$x_{35} = -43.016146575733$$
$$x_{36} = -111.016148295613$$
$$x_{37} = -31.01592600289$$
$$x_{38} = -99.0161482956131$$
$$x_{39} = -53.0161482657869$$
$$x_{40} = -115.016148295613$$
$$x_{41} = -81.0161482956127$$
$$x_{42} = -85.016148295613$$
$$x_{43} = -37.0161287111672$$
$$x_{44} = -67.0161482955109$$
$$x_{45} = -79.0161482956123$$
$$x_{46} = -77.0161482956113$$
$$x_{47} = -59.0161482929946$$
$$x_{48} = 1.70951129135145$$
This roots
$$x_{40} = -115.016148295613$$
$$x_{16} = -113.016148295613$$
$$x_{36} = -111.016148295613$$
$$x_{21} = -109.016148295613$$
$$x_{34} = -107.016148295613$$
$$x_{31} = -105.016148295613$$
$$x_{1} = -103.016148295613$$
$$x_{19} = -101.016148295613$$
$$x_{38} = -99.0161482956131$$
$$x_{5} = -97.0161482956131$$
$$x_{18} = -95.0161482956131$$
$$x_{28} = -93.0161482956131$$
$$x_{27} = -91.0161482956131$$
$$x_{30} = -89.0161482956131$$
$$x_{20} = -87.016148295613$$
$$x_{42} = -85.016148295613$$
$$x_{24} = -83.0161482956129$$
$$x_{41} = -81.0161482956127$$
$$x_{45} = -79.0161482956123$$
$$x_{46} = -77.0161482956113$$
$$x_{12} = -75.0161482956091$$
$$x_{32} = -73.0161482956041$$
$$x_{8} = -71.0161482955929$$
$$x_{22} = -69.0161482955677$$
$$x_{44} = -67.0161482955109$$
$$x_{15} = -65.0161482953832$$
$$x_{26} = -63.0161482950958$$
$$x_{13} = -61.0161482944493$$
$$x_{47} = -59.0161482929946$$
$$x_{11} = -57.0161482897215$$
$$x_{10} = -55.016148282357$$
$$x_{39} = -53.0161482657869$$
$$x_{29} = -51.0161482285041$$
$$x_{14} = -49.0161481446181$$
$$x_{6} = -47.0161479558756$$
$$x_{2} = -45.0161475312093$$
$$x_{35} = -43.016146575733$$
$$x_{25} = -41.0161444260271$$
$$x_{3} = -39.0161395897739$$
$$x_{43} = -37.0161287111672$$
$$x_{9} = -35.0161042493011$$
$$x_{17} = -33.0160492860239$$
$$x_{37} = -31.01592600289$$
$$x_{4} = -29.0156505597641$$
$$x_{33} = -27.0150406393294$$
$$x_{23} = -25.0137179041395$$
$$x_{7} = -23.0109910424438$$
$$x_{48} = 1.70951129135145$$
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
$$x_{0} \leq x_{40}$$
For example, let's take the point
$$x_{0} = x_{40} - \frac{1}{10}$$
=
$$-115.016148295613 + - \frac{1}{10}$$
=
$$-115.116148295613$$
substitute to the expression
$$- 2 \cdot 9^{x} + \left(6 \cdot 4^{x} + 6^{x}\right) \geq 0$$
$$- \frac{2}{9^{115.116148295613}} + \left(6^{-115.116148295613} + \frac{6}{4^{115.116148295613}}\right) \geq 0$$
2.96022011802196e-69 >= 0
one of the solutions of our inequality is:
$$x \leq -115.016148295613$$
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____
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x40 x16 x36 x21 x34 x31 x1 x19 x38 x5 x18 x28 x27 x30 x20 x42 x24 x41 x45 x46 x12 x32 x8 x22 x44 x15 x26 x13 x47 x11 x10 x39 x29 x14 x6 x2 x35 x25 x3 x43 x9 x17 x37 x4 x33 x23 x7 x48
Other solutions will get with the changeover to the next point
etc.
The answer:
$$x \leq -115.016148295613$$
$$x \geq -113.016148295613 \wedge x \leq -111.016148295613$$
$$x \geq -109.016148295613 \wedge x \leq -107.016148295613$$
$$x \geq -105.016148295613 \wedge x \leq -103.016148295613$$
$$x \geq -101.016148295613 \wedge x \leq -99.0161482956131$$
$$x \geq -97.0161482956131 \wedge x \leq -95.0161482956131$$
$$x \geq -93.0161482956131 \wedge x \leq -91.0161482956131$$
$$x \geq -89.0161482956131 \wedge x \leq -87.016148295613$$
$$x \geq -85.016148295613 \wedge x \leq -83.0161482956129$$
$$x \geq -81.0161482956127 \wedge x \leq -79.0161482956123$$
$$x \geq -77.0161482956113 \wedge x \leq -75.0161482956091$$
$$x \geq -73.0161482956041 \wedge x \leq -71.0161482955929$$
$$x \geq -69.0161482955677 \wedge x \leq -67.0161482955109$$
$$x \geq -65.0161482953832 \wedge x \leq -63.0161482950958$$
$$x \geq -61.0161482944493 \wedge x \leq -59.0161482929946$$
$$x \geq -57.0161482897215 \wedge x \leq -55.016148282357$$
$$x \geq -53.0161482657869 \wedge x \leq -51.0161482285041$$
$$x \geq -49.0161481446181 \wedge x \leq -47.0161479558756$$
$$x \geq -45.0161475312093 \wedge x \leq -43.016146575733$$
$$x \geq -41.0161444260271 \wedge x \leq -39.0161395897739$$
$$x \geq -37.0161287111672 \wedge x \leq -35.0161042493011$$
$$x \geq -33.0160492860239 \wedge x \leq -31.01592600289$$
$$x \geq -29.0156505597641 \wedge x \leq -27.0150406393294$$
$$x \geq -25.0137179041395 \wedge x \leq -23.0109910424438$$
$$x \geq 1.70951129135145$$