C++ Write a program that will perform the calculation y=6x^2-0.8x^3 for values of x from 1 to 20. Display the result of the calcuation, on separate lines, in the form "The result of "6*x*x-0.8*x*x*x=y for each value of x, where x is the value of the independent variable, and y is the calculated value. If the result is between 0 and -300 inclusive, then don't display the result. You must use both a repetition and a selection structure