20 1/19 -(x-4 17/19) =7 18/19 x=17. КАК правельно записать!?

20 1/19 - (x - 4 17/19) = 7 18/19;

(20 * 19 + 1)/19 - x + (4 * 19 + 17)/19 = (7 * 19 + 18)/19;

(380 + 1)/19 - x + (76 + 17)/19 = (133 + 18)/19;

381/19 - x + 93/19 = 151/19;

381/19 - 151/19 + 93/19 = х;

х = (381 - 151 + 93)/19 = (230 + 93)/19 = 323/19 = 17.