Explain how the chesapeake and north carolina colonies grew prosperous exporting tobacco.

In divergence to the northern and middle colonies, the southern and Chesapeake colonies, as well as Maryland, were mainly rural settlements. Maryland quickly prospered because, like its neighbor, Virginia, its economy was based on tobacco. The Chesapeake and North Carolina colonies were the example for large plantations and plantation-based economies. By growing a soon-to-be cash crop, these colonies required a lot of attention and hands-on labor that was supplied by enslaved Africans. These colonies helped expand Colonial America's export economy and other nations' dependence on similar crops and/or products grown here.

b. germany and italy

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