Первая цепочка:
\( 23 \times 3 = 69 \)
\( 69 + 31 = 100 \)
\( 100 + 420 = 520 \)
\( 520 : 10 = 52 \)
\( 52 : 13 = 4 \)
\( 4 + 676 = 680 \)
Вторая цепочка:
\( 160 - 80 = 80 \)
\( 80 - 80 = 0 \)
\( 0 : 20 = 0 \)
\( 0 + 19 = 19 \)
\( 19 + 23 = 42 \)
\( 42 - 49 = -7 \)
\( -7 + 1124 = 1117 \)
\( 1117 - 9 = 1108 \)
\( 1108 - 1113 = -5 \)