don't think you can simplify it
18/90=1/5
3/5
yes 2 over 5
7/90
no
No.
No
You can't simplify 4 over 90 as a whole number meaning 4 can't go into 90 evenly. So, the answer will be 22.5. That is your answer.
Yes. 5 and 20 are divisible by 5, so you can simplify 5/20 to 1/4.
It can be factored as 18(5-2x^2)
Yes, 2/2 is 1 and 90/2 is 45, so 2/90 is 1/45.
you can't.