The theory of mercantilism holds that a nation's economic power comes from a .

A. enslave people

B. become industrial

C. willingness to explore

D. favorable balance of trade

D.favorable balance of trade

Explanation:

The theory of mercantilism holds that a nation's economic power comes from a favorable balance of trade.The theory of mercantilism is a system based on the benefits of profitable trading in which a country attempts to amass wealth through trade with other countries

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