((3 1/2+(2/3)'2)*x+3/18=5/18.

(3 1/2 + (2/3)^2) * x + 3/18 = 5/18;

((3 * 2 + 1)/2 + 2^2/3^2) * x + 3/18 = 5/18;

(7/2 + 4/9) * x + 3/18 = 5/18;

(7 * 9/18 + 4 * 2/18) * x = 5/18 - 3/18;

(63/18 + 8/18) * x = (5 - 3)/18;

71/18 * x = 2/18;

х = 2/18 * 18/71 = (2 * 18)/(18 * 71) = 2/71.

Ответ: х = 2/71.