What is Value for N=3.5

Pepe is going to spin the following spinner 800 times. the spinner is divided into equal sections.a. exactly 160 timesb. clost to 160 times but probably not exactly 160 timesc. exactly 640 timesd. close to 640 times but not probably not exactly 640 times. me

Rewrite so the subject can be y in the formula d=m-y/y+n

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?