4. (7/12 + 5/9) : 1 7/9 + (2 1/2 − 1 1/3) · 9/14

\(\frac7{12}+\frac59=\frac{41}{36}\), поэтому \(\frac{41}{36}:1\frac79=\frac{41}{36}\cdot\frac9{16}=\frac{41}{64}\).

\(2\frac12-1\frac13=\frac76\), поэтому \(\frac76\cdot\frac9{14}=\frac34\).

\(\frac{41}{64}+\frac34=\frac{41}{64}+\frac{48}{64}=\frac{89}{64}=1\frac{25}{64}\).

Ответ: \(1\frac{25}{64}\).