0.3+2/7=4/5-0.3=1/12+0.1=3/4+0.85= помогите плизз

Question

0.3+2/7=
4/5-0.3=
1/12+0.1=
3/4+0.85= помогите плизз

Answer 1

1)0.3=3/10
3/10+2/7=21/70+20/70= 41/70
2)4/5=8/10=0.8
0.8-0.3=0.5
3)0.1=1/10
1/12+1/10=10/120+12/120=22/120=11/60
4)0.85=3/4
3/4+3/4=6/4=1.5