1) \( 38 - 18 = 20 \)
\( 20 + 9 = 29 \)
\( 29 - 14 = 15 \)
\( 15 - 25 = -10 \)
\( -10 + 37 = 27 \)
\( 27 - 50 = -23 \)
\( -23 + 68 = 45 \)
2) \( 49 + 1 = 50 \)
\( 50 - 34 = 16 \)
\( 16 - 57 = -41 \)
\( -41 - 28 = -69 \)
\( -69 + 16 = -53 \)
\( -53 - 45 = -98 \)
\( -98 + 39 = -59 \)
3) \( 24 - 19 = 5 \)
\( 5 + 66 = 71 \)
\( 71 + 24 = 95 \)
\( 95 - 38 = 57 \)
\( 57 - 40 = 17 \)
\( 17 + 71 = 88 \)
\( 88 - 80 = 8 \)
Ответ: 1) 45, 2) -59, 3) 8