Question

y varies inversely with x. Find the inverse variation equation if x = -10 when y = 4.
Answer

y/x = -2/5

xy = -40

y/x = -40

xy = -2/5

Answer 1

Since x and y are inversely related,
xy = k, where k is the constant of proportionality.
When x = -10, y = 4,
(-10)(4) = k i.e. k = -40
Thus, xy = -40