change dotnet version

Author: Trevor Bye

articles/cognitive-services/Speech-Service/spx-basics.md

@@ -24,8 +24,8 @@ The only prerequisite is an Azure Speech subscription. See the [guide](get-start
 
 SPX is available on Windows and Linux. Start by downloading the [zip archive](https://aka.ms/speech/spx-zips.zip), then extract it. SPX requires either the .NET Core or .NET Framework runtime, and the following versions are supported by platform:
 
-* Windows: [.NET Framework 4.7](https://dotnet.microsoft.com/download/dotnet-framework/net471), [.NET Core 2.2](https://dotnet.microsoft.com/download/dotnet-core/2.2)
-* Linux: [.NET Core 2.2](https://dotnet.microsoft.com/download/dotnet-core/2.2)
+* Windows: [.NET Framework 4.7](https://dotnet.microsoft.com/download/dotnet-framework/net471), [.NET Core 3.0](https://dotnet.microsoft.com/download/dotnet-core/3.0)
+* Linux: [.NET Core 3.0](https://dotnet.microsoft.com/download/dotnet-core/3.0)
 
 After you've installed a runtime, go to the root directory `spx-zips` that you extracted from the download, and extract the subdirectory that you need (`spx-net471`, for example). In a command prompt, change directory to this location, and then run `spx` to start the application.