1) 2x≥42x≥22x≥2;2^x\ge4 \\ 2^x\ge2^2 \\ x\ge2;2x≥42x≥22x≥2;
2) 0,5x≥42−x≥22−x≥2x≤−2 0,5^x\ge4\\ 2^{-x}\ge2^2 \\ -x\ge2 \\ x\le -20,5x≥42−x≥22−x≥2x≤−2
3) 0,5x≤42−x≤22−x≤2x≥−2 0,5^x\le4 \\ 2^{-x}\le 2^2 \\ -x\le 2 \\ x\ge -2 0,5x≤42−x≤22−x≤2x≥−2
4) 2x≤42x≤22x≤22^x\le4 \\ 2^x\le 2^2 \\ x\le22x≤42x≤22x≤2