I have forgotten some of the simplest things from my school days.

How would I go about getting rid of the denominator in a problem such as 2/t.

How would I solve a problem when there is a fraction in a fraction? I am doing derivatives and the actual problem is 2/t if t=1/2.

Using the formula f(x) lim h->0 f(x+h) - f(x)/h.