There isn't one. Those coordinates put you in Lake Michigan.
There's no city there. That point is out in the middle of southern Lake Michigan, about 22.8 miles west of the Michigan shore at Grand Mere State Park near Stevensville, and about 33.7 miles east of the Illinois shore at Hartigan Park in Chicago.
Chicago, IL
Unless you think there is a merman city at the bottom of Lake Michigan, there are no cities at those coordinates. 42° N, 87° W lies in the middle of the southern part of Lake Michigan. Evanston, Illinois lies at about 42° N, 87.7° W (N 42° W 87° 41') --- so about 42° N 88° W Chicago, Illinois lies at about 41.8°N, 87.6° W (N 41° 48' W 87° 36') --- so about 42° N 88° W Gary, Indiana lies at about 41.6° N, 87.4° W (N 41° 36' W 87° 18') --- so about 42° N 87° W --- the closest to a match. Michigan City, Indiana, Bridgeman, Michigan, and St. Joseph, Michigan also lie in the same vicinity.
The coordinates 14°N latitude and 87°W longitude point to a location in Central America, specifically in Honduras. This area is near the capital city, Tegucigalpa, but is not directly within the city itself. The coordinates fall within the vicinity of the La Paz department of Honduras.
The capital city located at 14 degrees north latitude and 87 degrees west longitude is Managua, the capital of Nicaragua. Latitude measures how far north or south a location is from the equator, while longitude measures how far east or west a location is from the Prime Meridian. Managua's coordinates place it just north of the equator and slightly to the west of the Prime Meridian.
Lake Michigan
There's no city there. That point is smack in the middle of the Bosten Hu lake, in northwestern China. It's about 125 miles south-southwest of the city of Ürümqi.
Chicago, the largest city in Illinois, is located at 42 degrees North and 87 degrees west. Chicago is located at the SW tip of Lake Michigan.
There is no city at 42°N 87°W. That location is the center of Lake Bostan in the Peoples Republic of China, about three and a half miles due east of the center of the city of Bohu.
45 -87 = -42
87+42+78 = 207
0.4828
42 N 87 W is Lake Michigan, United States.
Berrien County, MI, USA (Lake Michigan).
1, 87 can't be divded by anything other than 1 or 87 but that doesn't work with 42
-42
64