(1) The expression as you show it, "1.487^3-1/1.487^3+1", means .
I doubt that is what you intended. Use parentheses where required.
(2) You don't say what you/we are supposed to do with the expression.
(3) If you mean "(1.487^3-1)/(1.487^3+1)", or , and the question is simply to evaluate the expression, then use a calculator. You can do that as easily as we can.