Ответ:
1 - (70/35 - 11/35) : 9/25 + 4/21
1 - (59/35) : 9/25 + 4/21
1 - (59/35) * (25/9) + 4/21
1 - (59 * 5) / (7 * 9) + 4/21
1 - 295/63 + 4/21
1 - 295/63 + 12/63
1 - 283/63 = (63 - 283) / 63 = -220/63
1 - (59/35) : 9/25 + 4/21
1 - (59/35) * (25/9) + 4/21
1 - (59 * 5) / (7 * 9) + 4/21
1 - 295/63 + 4/21
1 - 295/63 + 12/63
1 - 283/63 = (63 - 283) / 63 = -220/63
