tolong jawab sekarang ya

20. 25%= 25/100÷25=1/4
0,125 = 125/1000÷25=5/40
1/4-5/40=10/40-5/40=5/40
5/40+1/3=15/120+40/120= 55/120÷5=11/24

21. -4 1/2 = -9/2
1 2/3= 5/3
-2 1/2= 5/2
-9/2×5/3=-45/6÷(-5/2)= -45/6 × (-2/5) = -90/30 ÷ 30 = 3