no
Do you mean five over three? If so that's 1.667.
YES
five over twelve is bigger than three over eight
the simplest form of four over five is....four over five. You can't reduce that fraction because it already is in simplest form.
14/15
1 7/12 (one and seven-twelfths)
5 over 55
The answer is three over five. It's original form is six over ten. (divide by two and you get three over five.)
-15
Divide both by four. The answer is five.
There is no meaningful question in "three over five y plus one over nine". There cannot, therefore, be an answer.
12.