Дробь 2-1:(1/2-1/4) _________ = 2+1:(1/2+1/4)
2-1÷(1/2-1/4) 1÷1/4 4 ---------------- = ---------- = ------ 2+1÷(1/2+1/4) 3÷3/4 4/3
2-1÷(1/2-1/4) 1÷1/4 4
---------------- = ---------- = ------
2+1÷(1/2+1/4) 3÷3/4 4/3