Which group of people on the great plains benefited most from the invention of barbed wire?
a cowboys
b native americans
c railroad workers
d farmers

Option:  D farmers    

Explanation:

The invention of barbed wire benefited most of the farmers because it allowed them to secure their property and manage cattle. The barbed wire was one of the inventions that changed the face of the great plains and the West forever. It allowed farmers to fence their property in the cheapest, strongest way. Since the plains were largely treeless, barbed wire performed their role in open-range cattle and farming.            

then its a law the end

simplify brackets

8 - 2a - 7 = a + 40

simplify 8 - 2a - 7 to -2a + 1

-2a + 1 = a + 40

add 2a to both sides

1 = a + 40 + 2a

simplify a + 40 + 2a to 3a + 40

1 = 3a + 40

subtract 40 from both sides

1 - 40 = 3a

simplify 1 - 40 o -39

-39 = 3a

divide both sides by 3

-39/3 = a

simplify 39/3 to 13

-13 = a

switch sides

a = -13