Answer:
x = 10
Step-by-step explanation:
Given y varies inversely with x then the equation relating them is
y = [tex]\frac{k}{x}[/tex] ← k is the constant of variation
To find k use the condition x = 2.5, y = 100, then
k = yx = 100 × 2.5 = 250
y = [tex]\frac{250}{x}[/tex] ← equation of variation
When y = 25, then
25 = [tex]\frac{250}{x}[/tex] ( multiply both sides by x )
25x = 250 ( divide both sides by 25 )
x = 10