. A. rotation 90º clockwise about the origin

When rotating a point 90 degrees counterclockwise about the origin our point A(x,y) becomes A'(-y,x). In other words, switch x and y and make y negative.

Explanation:

the installment plan of the 1920s, an arrangement that allowed people to buy what they wanted with a small down payment and pay off the rest in monthly installments, provided americans a way to own what they did not have the money to buy.

angel island immigration station was an immigration station located in san francisco bay which worked from 1910 to 1940. the majority of immigrants that got there were from the asian hemisphere, specifically from china, japan, russia, and south asia, being china the country from where more people arrived.

the number of foreigners arriving at it took the attention of americans who feared the new arrivals would take their jobs. the work opportunities were not abundant due to the economic comedown of 1870 and the asians, as newcomers, were willing to work for cheaper wages. soon they started to be seen as a threat, which led to an increased discrimination against the chinese - the biggest ethnicity arrived at this station until 1915 when japanese immigrants outnumbered them - being considered as unsuitable americans hence their looks and social situation.

at the station, the immigrant's detention may vary depending on how long the interrogation process took: it could be weeks, months, or even years.

finally, in 1940 an explosion destroyed administration building located on the island, so the united states government decided to stop the process.