Answer:
c = - 2
Step-by-step explanation:
calculate the slope m using the gradient formula
m = ( y₂ - y₁ ) / ( x₂ - x₁ )
with (x₁, y₁ ) = (8, 0) and (x₂, y₂ ) = (- 8, c)
m = =
=
cross- multiplying gives
8c = - 16 ( divide both sides by 2 )
c = - 2
part A
if the paperbacks are 40% less, that means 100% - 40% = 60%, they actually are 60% of the price of the hardcover ones.
part B
so, if they return it, they get 1/3 credit, if they try to sell it, is half off, which is more than 1/3. 22 got damaged.
part C
I don't think she is incorrect, $17.5 is close to $20, she didn't say it was exactly $20, just thereabouts, and 17.5 is around that much.