posted by SraJMcGinn on .
First: solve for k. Then, go back to the original equation c=k(d-3) and solve for c when d is ten.
Put in the fist conditions, solve for k.
Then, knowing k, solve for A when is eight.
1)if c varies directly as d-3, and if c=16 when d=7, find c when d=10
c=k(d-3) then 16=k(4)...how do u do this?
2)the surface area of a cube varies directly as the square of the length of one edge. if the surface area of a cube is 150 cm squared when the length of an edge is 5 cm, what is the surface area of a cube with an edge of length 8 cm?