Question

Please show how u got these answer TYSM because my teacher is Crazy about her work

1. 11+(20-13)
2. (10-7) - (14-12)
3. (4 + 17) - ( 16-9)
4. (23-15)- (18-13)

Answer 1

1. 20 - 13 = 7 | 7 + 11 = 18

2. 10 - 7 = 3 | 14 - 12 = 2 | 3 - 2 = 1

3. 4 + 17 = 21 | 16 - 9 = 7 | 21 - 7 = 14

4. 23 - 15 = 8 | 18 - 13 = 5 | 8 - 5 = 3