Which type of galaxy is very difficult to see, but (astronomers recently realized) may be very common

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

they bring people together to achieve control of the government

basically choosinng what sets in   congress and presdicny this is to keepthe antion hole and so it can last because wiht out authority it wouldnt last a week

woah dude who's thia? need more info