Hi

I am trying to model the change in lifetime versus mass and have the formula;

> T := 6.58*10^38*10^(-25)/x^3;
                                      
> plot(T, x = 10^10, 10^9, 10^8, 10^7, 10^6, 10^5, 10^4, 10^3, 10^2, 10, 10^0);
Error, (in plot) unexpected options: [x = 10000000000, 1000000000, 100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1]

I want to plot for values between x=10^-11 and 0, i have this error and i am not sure why.