Just a couple of simple questions I'm having trouble on.

6. y is directly proportional to the square of x, and y = 48 when x = 4. What is y when x = 24?

10. y is inversely proportional to x, and y = 32 when x = 4. what is y when x = 18?

Thanks.

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- Apr 17th 2008, 06:00 PMPandaPandaProportions
Just a couple of simple questions I'm having trouble on.

6. y is directly proportional to the square of x, and y = 48 when x = 4. What is y when x = 24?

10. y is inversely proportional to x, and y = 32 when x = 4. what is y when x = 18?

Thanks. - Apr 17th 2008, 06:02 PMcolby2152
- Apr 17th 2008, 06:03 PMJen
When something is directly proportional it means,

$\displaystyle y=kx$ where k is some constant.

Inversly proportional means,

$\displaystyle y=\frac{k}{x}$

so if y is directly proportional to the square of x then,

$\displaystyle y=kx^2$

Then use your values given to solve for K.

Hope that helps! :) - Apr 17th 2008, 06:14 PMPandaPanda
Thanks.

What confused me was there were problems stating "y varies directly/inversely with x" and "y is directly/inversely proportional to x"

What's the difference? - Apr 17th 2008, 06:50 PMJen