Express y in terms of x

Answer:
see explanation
Step-by-step explanation:
(a)
Given y is inversely proportional to x² then the equation relating them is
y = [tex]\frac{k\\}{x^2}[/tex] ← k is the constant of variation
To find k use any ordered pair from the table.
Using (1, 4 ) , then
4 = [tex]\frac{k}{1^2}[/tex] = [tex]\frac{k}{1}[/tex] ( multiply both sides by 1
4 = k
y = [tex]\frac{4}{x^2}[/tex] ← equation of variation
(b)
When y = 25 , then
25 = [tex]\frac{4}{x^2}[/tex] ( multiply both sides by x² )
25x² = 4 ( divide both sides by 25 )
x² = [tex]\frac{4}{25}[/tex] ( take the square root of both sides )
x = ± [tex]\sqrt{\frac{4}{25} }[/tex] = ± [tex]\frac{2}{5}[/tex]
Since x > 0 then x = [tex]\frac{2}{5}[/tex]