Найдем значение выражения при х = 4/16
$$18/16 - 3/16 * (16 + x) = 18/16 - 3/16 * (16 + 4/16) = 18/16 - 3/16 * (256/16 + 4/16) = 18/16 - 3/16 * (260/16) = 18/16 - (3*260)/(16*16) = 18/16 - 780/256 = (18*16)/(16*16) - 780/256 = 288/256 - 780/256 = (288-780)/256 = -492/256 = -123/64$$
$$= -1 \frac{59}{64}$$
Ответ: $$-1 \frac{59}{64}$$