Evaluate the contributions of significant political and social leaders such as andrew carnegie or shirley chisholm.

Andrew Carnegie was a Scottish-born American businessman who became rich thanks to his involvement in the steel business. Carnegie, however, invested in many different ventures and companies, including the railroad, cotton, iron and oil companies.

Carnegie is also remembered for his philantrophy. He believed it was the moral responsibility of rich people to distribute their money in a way that contributed to the welfare and happiness of all. Among his charitable enterprises were the establishment of more than 2,500 libraries, the donation of 7,600 organs to churches, and the land and construction costs of Carnegie Hall.

there has only been 12 presidents. the 12th president is/was moon jae-in

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