What was the Freedmen's Bureau's purpose and how did it accomplish it's
task?

The Bureau of Refugees, Freedmen, and Abandoned Lands, usually referred to as simply the Freedmen's Bureau, was a U.S. government agency from 1865 to 1872, after the Civil War, to direct "provisions, clothing, and fuel ... for the immediate and temporary shelter and supply of destitute and suffering refugees and ...

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.

for this case we have the following equation:

we apply distributive property to the terms within parentheses.

subtracting 2 on both sides of the equation: