Сначала выполним действия:
$$834 \times (145 \times 203 - 29130) + 804 \times 52 =$$
$$834 \times (29435 - 29130) + 804 \times 52 =$$
$$834 \times 305 + 804 \times 52 =$$
$$254370 + 41808 = 296178$$
Теперь выполним деление:
a) $$5/6:4/7 = 5/6 \times 7/4 = (5 \times 7)/(6 \times 4) = 35/24$$
б) $$6/35:48/49 = 6/35 \times 49/48 = (6 \times 49)/(35 \times 48) = (6 \times 7 \times 7)/(5 \times 7 \times 6 \times 8) = 7/(5 \times 8) = 7/40$$
в) $$8/15:32/75 = 8/15 \times 75/32 = (8 \times 75)/(15 \times 32) = (8 \times 15 \times 5)/(15 \times 8 \times 4) = 5/4$$
г) $$45/56:54/49 = 45/56 \times 49/54 = (45 \times 49)/(56 \times 54) = (5 \times 9 \times 7 \times 7)/(8 \times 7 \times 6 \times 9) = (5 \times 7)/(8 \times 6) = 35/48$$
Ответ: 296178; а) 35/24; б) 7/40; в) 5/4; г) 35/48