The Microsoft Bing Search app has a Math Mode which uses Bing’s Camera Intelligent search on iOS. It not only gives you the answer but also shows the method. This intelligent search meshes Microsoft’s AI with Visual Search technology to analyze the photo of the math problem and arrive at the answer. You can either snap a photo or use one in your phone’s media library.

Source: How to Solve Complex Math Equations With Bing

The app also shows your work, basically doing your math homework for you.