Hello, I wish to solve a simple equation. I tried solve and desolve to no avail. Can anyone please help? Here is the equation: 275.0*%e^(-r)+275.0*%e^(-2*r)+275.0*%e^(-3*r)+275.0*%e^(-4*r)+5275.0*%e^(-5*r)=4750.0 I am trying to determine the value of r. Julien.