Question

45+{15-[(10-8)+(7-4)-3]-4}

Answer 1

45 + {15 -[(10 - 8) + (7 - 4) - 3] - 4} =
45 + {15 - [2 + 3 - 3] - 4} =
45 + {15 - 2 - 2} =
45 + 11 = 56