tolong kak.. (tugas mandiri)

1. 20× 5= 100
5× 5= 25
100+ 25= 125
2. (50+10)/2 × 30= 60 × 15 = 900
15 × 10 = 150
900-150 = 750
3. 42 × 42 = 1724
22/7 × 1/2 × 21 × 21 = 693
1724 - 693 = 1031
4. 8 × 10 = 80
8× 6 / 2 = 24
80 + 24 = 104
5. 20 × 20 = 400
3,14 × 10 × 10 = 314
20 × 6 / 2 = 60
400 - (314 + 60) = 26
6. 16 × 5 = 80
3,14 × 1/2 × 2 × 2 = 5,88
80 - 5,88 = 44,12