Math help!?

Question

Each ordered pair is from an inverse variation. Find the constant of variation.

(0.2, 6)


(5/7,2/5)



Suppose x and y vary inversely. Write a function that models each inverse variation.

x=7 when y=2

x=-3 when y=8

x=1 when y=0.8

x=3/5 when y =5

x= -1/3 when y = 9/10

Answer 1

To find the constant of variation, use the form y = k/x. Just plug in for x and y, and you'll find k.

for (0.2,6),

6 = k(0.2)
k = 30


for (5/7, 2/5),

2/5 = k(5/7)
k = (2/5)(7/5) = 14/25

Do the same thing for the rest of them. Here, I'll do the first one for you:

2 = 7k
k = 2/7
function: y = 2/(7x)

That's how easy it is. Go for it!

Answer 2

k = 1.2

xy= =14
xy = -24
xy=.8
xy = 3
xy= -.3