PLEASE HELP ME ASAP I PUT THE WRONG SUBJECT ITS NOT HISTORY ITS ALGEBRA

Is the idea of containment relevant to american forge and policy today why or why not

Government powers not provided to the national government in the us constitution but are rather given to the states by the 10th amendment is called?

How did the completion of the transcontinental railroad change the lives of american citizens? a-it increased the wealth of all americans and enabled them to travel more.b-it made cross-country travel too expensive for ordinary americans.c-it decreased the safety of americans who moved to settle the plains.d-it shortened travel time between the east and west for all americans.