Grade 9 math question !

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BadWordBinch
I really need to know how to do this.

A parking meter contains $63.75 in quarters and loonies =. If there are 114 coins in the meter, how many quarters are there?

PLEASE tell me how you did every step. thanks.
 
There are 114 quarters, because loonies don't fit in parking meters no matter what they think.
 
It's an equation problem.

.25*X + 1*Y = 63.75

X + Y = 114

X = # quarters

Y = # dollar coins

You have two equations and two unknowns, substitue to solve for one variable in terms of the other, than solve the other eqaution.
 
^A Canadian joke.
You have two equations and two unknowns, substitue to solve for one variable in terms of the other, than solve the other eqaution.
You can also be clever and do it with one equation and one unknown. Should get the same answer, though.
 
Omnis- LOL true. i wouldnt try putting that as an answer on my exam though :/
Exorcet- Thanks, ill try different things with those formulas !! :D
Spacegoat- LMAO its a 1 dollar coin in Canada ahaha :)
Kylehnat- You can do that yourself if you like LOL
Barra333- you got it !
 
Hey would you look at that I'm in Grade 9. Whoo.

Pretty much this:
.25x + 1y = 63.75
x + y = 114

Now do this:

4(.25x + y = 63.75)----------------------x + 4y = 255
1(x + y = 114)-------------------------x + y = 114 ------------------SUBTRACT

3y = 141
Divide both sides by 3
y = 47

x + 47 = 114
-47 -47

x = 67

Hope that makes sense. 👍
 
Hey would you look at that I'm in Grade 9. Whoo.

Pretty much this:
.25x + 1y = 63.75
x + y = 114

Now do this:

4(.25x + y = 63.75)----------------------x + 4y = 255
1(x + y = 114)-------------------------x + y = 114 ------------------SUBTRACT

3y = 141
Divide both sides by 3
y = 47

x + 47 = 114
-47 -47

x = 67

Hope that makes sense. 👍

Nice Job 👍, once i understood how you portrayed the working (aka figured out that you were subtracting one equation from the other) it all made perfect sense..
 
Shouldn't you be doing you own homework, Z o n d a? ;)
 
No prob. I just got out of Algebra 1 two weeks ago, I surely picked up something while I was there.

He TB, I've done a lot of classwork for a lot of people. Just comes naturally to me.
 
I wish I could go back! I'm probably going to get destroyed by my AP stats and AP calc finals.
 
Here's another way to do it. Should be easy enough to translate to python, perl, whatever language floats yer boat:

Code:
<?php
for ( $loonie = 114, $quarter = 0; 100 * $loonie + 25 * $quarter > 6375; $loonie--, $quarter++ )
    ;
printf( "%d loonies, %d quarters\n", $loonie, $quarter );
?>
 
TB
Shouldn't you be doing you own homework, Z o n d a? ;)

That's what I was thinking. Give him a hint, at most. Why work it out for him? What's he gonna do the next time?

I think his problem isn't so much that he doesn't know how to work out a two-variable problem, I think he just couldn't translate the word problem into the math expressions. Word problems kill people, for some reason.

You can also be clever and do it with one equation and one unknown. Should get the same answer, though.

With that, all you're really doing is starting with the substitution for Y already done, i.e. mentally skipping part of the problem. The fact that it asks for how many quarters doesn't mean that "how many dollar coins" is not part of the problem.
 
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It's true...I was doing the second equation in my head at the very start when I set up the problem. I've done it so much at work, it's just become a habit :lol:. x + (1-x) = 1 comes up way too often ;).
 
The last thread where someone asked GTP to do their homework for them was shut down instantly. Why are you guys encouraging him? If you don't know the answer, than I'm sure your school offers after school tutoring.
 
That's what I was thinking. Give him a hint, at most. Why work it out for him? What's he gonna do the next time?

I think his problem isn't so much that he doesn't know how to work out a two-variable problem, I think he just couldn't translate the word problem into the math expressions. Word problems kill people, for some reason.

Some people learn better from just seeing clearly how a problem is solved, reviewing the steps, and then applying the process to other problems. And often, text books aren't the best with their examples, from what I've seen in my time - they are either very unique cases or absurdly simplified.

It isn't just like the answer was given to him, it was a clear explanation.
 
This was fun to do again. :)

X = number of quarters
Y = number of loonies (dollars)
(i.e. X = 0.25Y)

X + Y = 114
=> Y = 114 - X

0.25X + Y = 63.75
=>

0.25X + 114 - X = 63.75
(0.25 - 1)X + 114 = 63.75
-0.75X = -50.25
X = -50.25 \ -0.75
X = 67

and
Y = 114 - 67 = 47
 
I often have to see examples fully worked out. It helps me get the problem started, and I can figure out how to get from one step to the other pretty well. After using that a few times (or a lot of times with recent hard stuff) I'll be able to recognize the situation and run through them on my own.
 
Yeah, that's generally what they do in class, while the kids are texting or Facebooking on their phones.
 
Or legs, yes. We didn't have the internet in our pockets when I was distracted in school. With what we did have, you couldn't exactly look up what you were supposed to be learning. Kids got it so easy these days.
 
LOLLL, well i needed to know this cause i just did my math exam today.. and it was easy. no questions were more complicated than this surprisingly lol.
And i did get the answer but the only problem was it keep being -47 for some reaosn but i dont even care lol

AND indeed, i do stare at tits and asses. (mostly tits) lol jk (maybe, maybe not)
 
Or legs, yes. We didn't have the internet in our pockets when I was distracted in school. With what we did have, you couldn't exactly look up what you were supposed to be learning. Kids got it so easy these days.

It's kind of funny to see how much effort teachers put into trying to put down the phone epidemic. It truly is annoying to me because I don't want to be interrupted every 5 minutes, because I'm either gazing at the board or at women and that interruption spoils everything. Guess technology's bested us people.

As for me, I don't use my phone in school, I take it but I don't get texting in school.
 
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