18 + 24 - 7 =; 45 - 12 + 16 =; 6 × (9 - 4) =; 54 : (6 + 3) =; 42 - (14 + 8) =.

Решение

\( 18 + 24 - 7 = 42 - 7 = 35 \)

\( 45 - 12 + 16 = 33 + 16 = 49 \)

\( 6 \times (9 - 4) = 6 \times 5 = 30 \)

\( 54 : (6 + 3) = 54 : 9 = 6 \)

\( 42 - (14 + 8) = 42 - 22 = 20 \)

Ответ: 35, 49, 30, 6, 20.