SOLUTION: I can't figure this out for the life of me...HELP!!! This has to do with direct and inverse variation. The problem is: x varies directly as the square of s and inversely as t.

Question 125838: I can't figure this out for the life of me...HELP!!! This has to do with direct and inverse variation.
The problem is: x varies directly as the square of s and inversely as t. How does x change when s is doubled? When both s and t are doubled?
Please help me.
Found 2 solutions by Earlsdon, josmiceli:
Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
You can express "x varies as the square of s and inversely as t" like this:
k is the constant of variation.
To see how x changes when s is doubled (2s), simply substitute 2s for s in the above formula and simplify.

but, as you can see, the factor in parentheses () is the original x, so...
or, in words, x is quadrupled when s is doubled.
Now, when both s and t are doubled, substitute 2s and 2t for s and t respectively in the first formula:

Simplify.
Cancel 2's in the top and bottom.
or...
so you see that x is doubled when both s and t are doubled.
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
You can write an equation using what is called "the constant
of proportionality " Since there are 2 equations, I'll
use 2 constants and

------------------
The constants have to stay constant, so

If I double

must be multiplied by so that gets
multipied by and does not change
-------------------
If both s and t are doubled:

You can see that must be multipied by so that
will stay the same. So gets multipied by and
or is doubled. answer

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