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-[5-3]-4}
45+{15-2-4}
45+{13-4}
45+9
54

Answer 2

45+{15-[(10-8)+(7-4)-3]-4}=45 + {15 - [ 2 + 3 - 3] - 4} =
45 + { 15 - [2] - 4 =
45 + 9 = 54