Under the entry slot is a link labeled Examples.
That opens a page of topics for which there are examples prepared.
Clicking the Algebra link opens a page with many examples of entering algebra problems,
http://www.wolframalpha.com/examples/Algebra.html
If the Examples don't help, you can ask Wolfram|Alpha staff via the "Give us your feedback" slot at the bottom of an output page,
or by email to info@wolframalpha.com . (Email would let you attach a screen shot. The feedback slot automatically includes the input line.)
As Priyan said, a specific example is valuable.