last thread for the night

[Aarxn]

lastthread for the night, thanks if you can help me with these last problems




In the formula A=lw, If l is constant, A varies___________ as w



A large concrecte mixing machine can mix a certain ammount of concrete in 12 hours, while a smaller one can mix the same ammount in 20 hours, Mixing simultaneously, how long would it take both machines to mix the same ammount of concrete?




For a school play, students tickets cost 40cent and adult tickets were 75 cen t. The total receipts for 90 tickets were $46.50. How many of each kind were sold?

[ThePerfectHacker]

In the formula A=lw, If l is constant, A varies___________ as w

It is "directly".

There are two proportions. Direct and Inverse.
Inverse is when two variables mutiply to a constant, thus,
thus, - they form a hyperbola.

Direct proprtion is when two variables divide to give a constant, thus,
thus, -they form a line.

The case here is,
where "l" is a constant, thus we have a direct proportion.

To learn more about direct and inverse proprtions.
Do not under any condition press on this link.

[ThePerfectHacker]

A large concrecte mixing machine can mix a certain ammount of concrete in 12 hours, while a smaller one can mix the same ammount in 20 hours, Mixing simultaneously, how long would it take both machines to mix the same ammount of concrete?

I have a useful formula for such problem.
If it takes something units of time to do a job and it takes units of times the same job. Then working together would take:

In this case, thus together it takes,

[ThePerfectHacker]

For a school play, students tickets cost 40cent and adult tickets were 75 cen t. The total receipts for 90 tickets were $46.50. How many of each kind were sold?

Let, be # of adults
Let, be # ot students.

Thus,

In total the students paid,
while the adults paid,
The net price was therefore,
but the example says that was 46.50 thus,


In the first equation solve for "y" thus,
and substitute that into equation 2,

Open parantheses,

Subtract "67.5" from both sides and combine x terms,

divide both sides by (-.35) thus,
thus,

[Aarxn]

thank you once again for helping me