Answer:
The other places were The Caribbean and South America.
Explanation:
Huge numbers of slaves were imported by South America and the Caribbean during the nearly four centuries when slavery as practised in the American continents. Some estimates put the import numbers as high as 55 percent of all slaves imported to have been done by Spanish America and Brazil. The lowlands of Brazil and the fertile lands of the Caribbean were where plantation economies thrived due to the climate, land, and waterways that eased transportation.
ST=21, SP=3b-11, PT=B+4
ST=SP+PT
21=(3b-11)+(b+4)
21=3b-11+b+4
21=4b-7
21+7=4b
4b=28
b=7
