tolong dibantu ya bro

7/2+25/4-8/3=42/12+75/12-32/12
=85/12
=7 satu/12

1)4/5×20/20=80/100=80persen
2)3 1/2+6 1/4-2 2/3=7 6+3-8/12=7 1/12
3)2/3:4/12×1/8=2/3×12/4×1/8=4/16
4)2/2+3×100=40