posted by stressed on .
I have no clue what to do here can you tell me how to figure this?
If y varies directly with x, and y = 500 when x = 200, find the constant of variation k.
Whenever you have a statement such as
"....y varies directly with x..."
you can write it as an equation y = kx, where k is some constant
so in your case they give you x=200, y=500
sub those values into the equation and you can solve for k
This is an example of a direct variation.
You can also have an "inverse variation", such as...
"The Time taken for a trip varies inversely with the speed"
then your equation would be Time = k(1/speed), again where k is some constant.