What is 2/4 in simplest form

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

What is the product? a-3/15a × 5/a-3

Find the equation of the ellipse with the following properties. the ellipse with foci at (0, 6) and (0, -6); y-intercepts (0, 8) and (0, -8).edit: the answer is x^2 over 28 + y^2 over 64 = 1