Part A:
The inference that can be made about the educational system in the United States from "President Obama's Third Annual Back to School Speech" is:
It needs improvement.
Part B:
The detail from the speech that best supports the inference in Part A is:
“We’re taking every step we can to ensure that you’re getting an educational system that is worthy of your potential.”
This statement implies that there is a recognition of the need for improvement in the educational system, as the government is actively working to make it better.