P& g's biggest hurdle to overcome when selling tampons in latin american markets was

P&G had to overcome mostly religious and cultural hurdles. The biggest hurdle was that a lot of women thought that if they use tampons, they will loose their virginity. And in a majority Catholic continent such as Latin-America, virginity is really important; therefore many women restraint to use tampons for that reason. 

four sitting presidents have been assassinated while in office but the first was abraham lincoln,

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