3^ (-x+13) >7293^(-x + 13) > 3^6-x+13>613-6>xx<7x∈(-∞;7)2^x +2^(x+2) >6402^x + 2^x × 2^2 > 6402^x × (1 + 2^2) > 6402^x × 5 >6402^x > 640/52^x > 1282^x > 2^7x>7x∈ (7; +∞) 4^x +4^(x+2) <2724^x + 4^x × 4^2 <2724^x × ( 1+ 4^2) < 2724^x × 17 < 2724^x < 272/174^x < 164^x < 4^2x<2x∈ (-∞ ; 2 )(1/3)^x + (1/3) ^(x+1) ≤ 12(1/3)^x × (1 + 1/3 ) ≤ 121/3 ^x ≤ 12 ÷ 1 1/31/3 ^x ≤ 12/1 * 3/43^(-x) ≤ 9 3^ (-x) ≤ 3^2-x≤ 2x ≥ - 2x∈ [ - 2 ; +∞)2 × (1/5) ^ (-2x - 18) > 12505^ ( - 1*( -2x -18)) > 1250/25^ (2x +18) > 6255^(2x+18) > 5^42x + 18 > 42x > 4 -18x> -14/2x > - 7x (- 7 ; + ∞)