tolong bantu jawab soal matematika 7-10 :)

7. 20/100×200.000=40.000
200.000-40.000= 160.000

8. 4 1/5 = 5×4+1/5= 21/5 = 4,2

9. 2 1/2×10/15=2×5/3×5=5/2×2/3=10/6=1 2/3

10. 0,125:0,5=0,25