3 ^ (2 * x − 5) + 3 ^ (2 * x − 6) − 3 ^ (2 * x − 7) − 3 ^ (2 * x − 8) < = 32;3 ^ (2 * x) * 3 ^ (- 5) + 3 ^ (2 * x) * 3 ^ (- 6) - 3 ^ (2 * x) * 3 ^ (- 7) - 3 ^ (2 * x) * 3 ^ (- 8) < = 32;3 ^ (2 * x) * 3 ^ (- 5) * ( 1 +1 / 3 - 1 / 9 - 1 / 27) ) < = 32; 3 ^ (2 * x) * 3 ^ (- 5) * ( (27 + 9 - 3 - 1) / 27 ) < = 32; 3 ^ (2 * x) * 3 ^ (- 5) * ( 32 / 27 ) < = 32; 3 ^ (2 * x) * 1 / 3 ^ 5 * ( 32 / 27 ) < = 32; 3 ^ (2 * x) * 32 < = 32 * 3 ^ 5 * 27; 3 ^ (2 * x) * 32 < = 32 * 3 ^ 5 * 27; 3 ^ (2 * x) < = 3 ^ 5 * 27;3 ^ (2 * x) < = 3 ^ 5 * 27;3 ^ (2 * x) < = 3 ^ 5 * 3 ^ 3;3 ^ (2 * x) < = 3 ^ (5 + 3);3 ^ (2 * x) < = 3 ^ 8;2 * x < = 8;x < = 4.