
If I understood correctly and didn't make any mistakes...
To find the decimal value, we must convert 1/2 and 3/4 into decimal.
1/2=0.5
3/4=0.75
Now we just have choose a random decimal in between the decimal.
Let's choose 0.6
Now we have to convert the decimal into a fraction. So we'll multiply the decimal by100.
0.6×100=60
Then we make the 60 into a fractions. 60/100
Then we'll simply the fraction. 60/100÷10=6/10÷2=3/5
There you go. You have your answer.
Here's what I got for the first question.
Did you want answers for the second one? I couldn't read that part of the image very well, if you did.
For

, we have

and so

which is, again, only valid for

.