# rate of change and functions

• Jan 31st 2010, 10:36 AM
jacielmc
rate of change and functions
One printer (z) can print out x characters per second, and a second printer(w) can print y characters per second. If the first prints for 50 seconds, and the second for 60 seconds to make a total f 12200 characters, find the equation relating x and y.

x(50)+y(60)=12200
t(1)+t(2)=110 seconds.
but i don't get how to blend them to one function.
• Jan 31st 2010, 10:40 AM
skeeter
Quote:

Originally Posted by jacielmc
One printer (z) can print out x characters per second, and a second printer(w) can print y characters per second. If the first prints for 50 seconds, and the second for 60 seconds to make a total f 12200 characters, find the equation relating x and y.

x(50)+y(60)=12200 this answers the question ... you're done.

...
• Jan 31st 2010, 10:42 AM
1005
Quote:

Originally Posted by jacielmc
One printer (z) can print out x characters per second, and a second printer(w) can print y characters per second. If the first prints for 50 seconds, and the second for 60 seconds to make a total f 12200 characters, find the equation relating x and y.

x(50)+y(60)=12200
t(1)+t(2)=110 seconds.
but i don't get how to blend them to one function.

$\displaystyle 50x + 60y = 12200$
If you solve for x or y, you then have a function of y or x that is related to x or y.
$\displaystyle y = \frac{12200 - 50x}{60}$

edit: Yeah, like the person above me said, you can stop at $\displaystyle 50x + 60y = 12200$, and you're done.