What is true about traditional economies? They produce only enough to keep their families alive.
They use money to sell and make a profit.
They live in urban, developed areas.
They produce more than they need.

united states reinforcements contributed greatly to three allied victories in france at: cantigny (first major american battle), argonne (the largest in the united states military history, involving 1.2 million american soldiers), and château-thierry (one of the first actions under general pershing).

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