Question 887482: If y varies inversely as x, and y=18 when x=3, find when x=8
Answer by DrBeeee(684)   (Show Source):
You can put this solution on YOUR website! When y varies inversely with x we have
(1) y = c/x, where c is a constant.
When x = 3 we are given that y equals 18 or
(2) 18 = c/3 or
(3) c = 3*18 or
(4) c = 54, giving us the inverse equation
(5) y = 54/x
You are asked to find y when x = 8, so put x into (5) and get
(6) y = 54/8 or
(7) y = 27/4 or
(8) y = 6.75 or
(9) y = 6 3/4
|
|
|
