tolong Di Jawab !!! Juga caranya ya!!!

1. 2/7x42=12. 42-12=30

2. 3/5 (x) =210000 maka x = 210000x5/3=35000

3. 1+3+5+7+9+11+13+15+17+19+21=121

4. 36=2²x3² dan 45= 3²x5 kpk = 2²x3²x5=180

6.4x3x75000=900000

7. 3/8x64=24

8.25%=0,25 ,1/3=0,33 ,0,32 jadi urutannya 25%, 0,32 , 1/3

10. 18= 2x3² ,24=2³x3 fpb = 2x3=6

11. √169-√121= 13-11= 2

12. K= 3x6,75=20,25

16. untung = 25/100x300000=75000

18. x= 490000/7=70000
uang ani =4x70000=280000

19. 12 1/4 -8 3/5=49/4-43-5=245/20-172/20=73/20= 3 13/20

20. 15 1/3+ 9 7/15=24 5/15+7/15=24 12/15