Gabrielius T.

asked • 02/08/20

Algebra inequality

I happened to deal with this algebra inequality 8/x>0 and the answer seems obvious in interval notation, it's (0;∞), but then I check with online problem solver website Cymath and there it gets strange. It replaces the inequality sign with an equal sign, then multiply both sides by x and since 8=0 is false, there is no solution. I think this method is mathematically correct. So why does this mess exist?

David W.

tutor
I just tried x/8 > 0 and it did not replace the > with =. I would contact Cymath and bring up your concern. While it might make it easier for someone just learning it to understand, there is no need for the substitution.
Report

02/08/20

David W.

Note: (0,∞)
Report

02/08/20

LEV K.

tutor
It is not! mathematically correct to multiply by x. If x>0 and you multiply by x - the inequality doesn't change the direction. On the other hand, if x<0 and you multiply by x - the inequality changes from > to
Report

02/09/20

1 Expert Answer

By:

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.