Check out example codes for "ERROR in node_modules/rxjs/internal/types.d.ts(81,44): error TS1005: ';' expected.". It will help you in understanding the concepts better.
Code Example 1
This problem might arise due to version mismatch. To solve your problem you need to do following changes in your package.json file. Go to package.json and modify "rxjs": "^6.0.0" to "rxjs": "6.0.0" then npm update then ng serve
Learn ReactJs, React Native from akashmittal.com