Charles Darwin visited the Galapagos islands in the 1800's. These islands are just millions of years old (compared with Earth being 4.6 billion years old). How did this archipelego of islands form? They are from erosion of soil They were formed from volcanic eruptions They were formed from Glaciers depositing the debris there.

explanation:

queer

answer: my personal opinion is the black spider because he is more powerful than spiderman.

opinion because one person might not like silk

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