Home > Algebra > Inverse Variation Models

If x varies inversely as y and y=40 when x=4, how do you find x when y=20?

Answer 1

Eli Assouline

To find x when y=20, we can use the inverse variation formula: x1 * y1 = x2 * y2.

Given that y varies inversely as x, we have y1 = 40 and x1 = 4.

Plugging these values into the formula, we get: 4 * 40 = x2 * 20.

Simplifying the equation, we have: 160 = x2 * 20.

To find x2, we divide both sides of the equation by 20: x2 = 160 / 20.

Therefore, x2 = 8.

So, when y=20, x=8.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Hazel Anglin

I didn't understand well the question but I think is about direct and inverse proportion.

X is inversly proportional to Y #x=k/y#

#x=4# #y=40#

#4=k/40#

#k=40X4=160#

#x=160/y#

#y=20#

#x=160/20=8#

Answer: #x=8# #y=20#

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.