Which of these innovations was spread to southern africa as a result of the bantu migrations? a.) gunpowder. b.) iron working. c.) crop rotation. d.) subsistence farming.

The correct option is D subsistence farming. One of the innovations spread to Southern Africa as the result of the migration of Bantu-speaking people, which was a series of migration of the proto-Bantu language speaking group from central Africa across the sub-Sahara Africa, was the introduction of new farming techniques.  

Agriculture and farming techniques improved thanks to the ability of Bantu-speakers to reproduce and expand more quickly, surviving thanks to the plants and animals spread and cultivated by them.

what are the options ?

the perimeter of a triangle is 69 cm. side a is 5 cm shorter than side b. side c is twice as long as side a. find the length of each side. i need to know how to do it in 2 equations.  

equations:

a = b-5

c = 2a

a + b + c = 69