Suppose y varies inversely with x and y = 5 when x = 7 Part A) Write an equation that models the variation. (1 point) Part B) Find x when y = 140. (1 point)
Part A) The equation that models the variation is y = k/x, where k is the constant of variation.
To find the value of k, use the given information y = 5 when x = 7:
5 = k/7
k = 35
So, the equation that models the variation is y = 35/x.
Part B) To find x when y = 140, plug in y = 140 into the equation y = 35/x and solve for x:
140 = 35/x
x = 35/140
x = 1/4
Therefore, x = 1/4 when y = 140.