Question

y varies inversely as three times x. When x = 6, y = 4. Find x when y = 8. i need help please

Answer 1

inverse variation means the product is constant, so y • 3x = k

then 4 • 3(6) = k = 8 • 3x
∙ ∙ ∙ ∙ ∙ ∙ 72 ∙ ∙ ∙ = ∙ ∙ 24x
∙ ∙ ∙ ∙ ∙ ∙ ∙ ∙ ∙ ∙ 3 = x

Answer 2

how about y varies directly as the square of x. When x = 2, y = 40. Find x when y = 640.

Answer 3

y varies directly as the square of x. When x = 2, y = 40. Find x when y = 640.
x = ±6
x = ±8
x = ±12
x = ±20

answer x = ±8