Suppose y varies directly with x, and y = 25 when x = 140. What is the value of x when y = 36?
Since y varies directly with x, we can set up the direct variation equation as follows:
y = kx,
where k is the constant of variation. To find the value of k, we can use the given values y = 25 and x = 140:
25 = k(140).
Dividing both sides of the equation by 140, we have:
k = 25/140 = 5/28.
Now we can use the value of k to find the value of x when y = 36:
36 = (5/28)x.
Multiplying both sides of the equation by 28/5, we get:
(28/5) * 36 = x.
Simplifying the equation, we find:
201.6 = x.
Therefore, when y = 36, the value of x is 201.6.