What was the main negative impact of the invention of the cotton gin?
it created pollution because it was powered by fuel.
it caused massive population growth in the southern states.
it increased the demand for slaves and made slaves more valuable.
it required interchangeable parts which were expensive to produce.

The answer is C.  It increased the demand for slaves and made slaves more valuable.

I Hope This Helps!

the answer is prolly b

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