There is no way other than approximation by series or iterative methods, because it is an irrational number. 0.6989700043360188047862611052755069732318101185378914586895725388728918107255754905130727478818138279593155228085690046209052321188664764940003076662953044249354970357458065973381802656883970564988160971018214173828455604681380... The "solution" above uses e, but there is no way to find e other than by approximation by series or iterative methods, because it is an irrational number. It only uses e to 3 decimal places. Edwin