(1 – 4 / 9) / (1 / 3 – 1 / 4)

1)1 - 4/ 9 = 1·9/ 9 - 4 /9 = 9 /9 - 4/ 9 = 9 - 4/ 9 = 5 /9 2)1/ 3 - 1/ 4 = 1·4/ 3·4 - 1·3 /4·3 = 4 /12 - 3 /12 = 4 - 3 /12 = 1 /12 3) 5 /9 ÷ 1/ 12 = 5/ 9 × 12/ 1 = 5·12 /9·1 = 60 /9 = 20·3/ 3·3 = 20/ 3 = 2 + 6·3 /3 = 6 2/ 3 (1 – 4 / 9) / (1 / 3 – 1 / 4) = 6 2/3