Question

If y varies inversely as x, find the constant of variation if y = 5 when x = -1?? Stuck on this

Answer 1

y varies inversely as x means \[\huge y = \frac kx\]

when y = 5 then x = -1 means \[\huge 5 = \frac k{-1}\]
solve for k <--that's the constant of variation

Answer 2

So do I divide it or do I add?

Answer 3

cross multiply 5 and -1 to get k

Answer 4

-5 :D!

Answer 5

right

Answer 6

Now do the same thing to this problem? Write the appropriate direct variation equation if y = 8 as x = -4?