Suppose that y varies inversely with x and that y = 2 when x = 8. What is an equation for the inverse variation?

Question

What would the answer be?

What is the factored form of the expression?

s^2 – 81

(s – 9)(s – 9)
(s – 9)(s + 11)
(s – 9)(s + 9)
(s + 9)(s + 9)

I think that it is B. Is that right?

Answer 1

y = k/x
2 = k/8
k = 16
y = 16/x

a^2-b^2 = (a-b)(a+b) always