Question

If m = 2 when n = 7 and m varies inversely with n, then find m when n = 8.
A. 14
B. 7/4
C. 2
D. 7/2

Answer 1

(m)(n) = k -> (2)(7) = k -> k = 14

(m)(n) = 14 -> (m)(8) = 14 -> m = 14/8 = 7/4

Answer 2

The inverse relationship is from :

(m)(n) = k

When m gets bigger, n gets smaller and vice versa.

Answer 3

just like x and y?

Answer 4

Yes, just like one of the previous problems. x, y, m, and n are "dummy" variables.

Answer 5

oh okay

Answer 6

There is nothing magical about "k". It happens to be the constant, but we could have used another symbol.

Answer 7

so it really doesn't matter what letter we use?

Answer 8

as long as you have two that represent x and y

Answer 9

That's right. There are some conventions that are in use, like "x" and "y" in the coordinate plane, but those are really dummy variables. All variables are "dummy". They are just a convenience to hold something. This is different than using a symbol for a constant though.

Answer 10

oh alright
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