cara penyelesaian nya gimana teman teman?

1)
3/20+9/10-13/20
=3/20+18/20-13/20
=8/20

2)
4/6-1/4-1/24
=16/24-6/24-1/24
=9/24

Jawab:
1.3/20+9/10-13/20=3/20+18/20-13/20=8/20=0,4
2.45.000×5/9=25.000
3.3,4+0,85-39/25=3,4+0,85-1,56=2,69
4.19/8 ×8/15=152/120=1 32/120=
5.2/3×6/7×2/8=24/168
6.7/28×100=25%
7.50/3=16,66
8.1,575-0,675=0,9
9.7/4+11/2=7/4+22/4=29/4=7 1/4
10.4/6-1/4-1/24=16/24-6/24-1-24=9/24

Mohon maaf Jika Salah
Semoga Membantu dan Terbaik :)