# Understanding the Reduce error message

I am trying to execute the below expression expecting Reduce[] to provide a range for n1 and n2 that satisfies the inequality.

Reduce[0.49 - 0.4 0.9^n2 - 0.01n1 > -4.41, {n1, n2}]


I get the below error message:

Reduce::inex Reduce was unable to solve the system with inexact coefficients or the system obtained by direct rationalization of inexact numbers present in the system. Since many of the methods used by Reduce require exact input, providing Reduce with an exact version of the system may help.

Can someone please explain me this and guide me how to resolve this?

• Reduce can not find a solution neither with inexact coefficients nor with rational numbers. Try FindInstance[0.49 - 0.4*0.9^n2 - 0.01 n1 > -4.41, {n1, n2}] – rmw Nov 14 '18 at 21:33
• @rmw, thank you. This provides a single instance. Is there any other function that will provide the range of values for which this is true? – gaganso Nov 14 '18 at 23:08
• To get exact coefficients use Rationalize; however, that will not necessarily address the underlying issue of whether Mathematica can solve the inequality. – Bob Hanlon Nov 15 '18 at 5:12