Sunday, February 04, 2007

Neuvième Mathématiques KCVI '06/'07

Si vous avez des questions vous pouvez les demander ici.

28 comments:

Anonymous said...

is there a typo on the answers for question 7a) on the test solutions page for the test that we did on thursday?(x+3x '+' 5...)- Julianne

ms.bearse said...

Thanks Julianne, there was a typo. I have reposted the solutions now. I'm glad you are working so hard :)

Ms. Bearse

Rosie said...

Hey madame Bearse,

I having problems with question 16 in the homework. I tried to do question a) but couldn't get it and when I looked in the answers I didn't understand how they got that chart. help!!!
Rosie

ms.bearse said...

for 16 a) there are several possibilities.

The total amount of money he is getting is 180 dollars. He must work whole numbers of hours (no half hours etc) at each job.

One possibility is if he works all his hours at the job that pays $10/h. If he works 18 hours there, he's going to make 180 dollars.

So now we can try him working at both jobs. How about him working 4 hours at the $7.50/hour job. That will earn him 30 dollars. He has to earn 150 more dollars, so that's 15 hours at the job paying $10/h

He could also work 8h at the 7.50 job and earn 60 dollars. Then he will have to make 120 at the other job, which is 12 hours.

The key is to find situations with whole number of hours.

It wouldnt work if he worked for 1 hour at the $7.50/h job. He would then need to earn 172.50 from the other job. He would then need to work 17.25 hours...but he needs whole number hours, so we have to eliminate this from our list.

Does that help?

Rosemary said...

Yes it does help, thanks!! But I was wondering, the test tomorrow just deals with equations but no fraction equations and it won't contain word problems?
Thank you so much for all your help!
Yours,
Rosie

ms.bearse said...

The test will not have equations with fractions. The answers that you get might be fractions though.

Example:
3x=12 you divide each side by 3, so x=4

if you had 3x=13, and you divide each side by 3, so x=13/3. (the answer is a fraction...but that's ok)

Word problems will be the focus of the next test. This test may have some translating from french to math, and also some setting up equations given a problem, but it is not the main part of the test. The main part of this test is working with the equations, solving to find x, substituting a value (like question 17 from the homework tonight).

I think you are ready...you worked hard today in class and at lunch too!

Rosemary said...

Dear Mme. Bearse
I'm having problems with the homework especially number 4. I copied the notes down in class but I only know how to solve the equations when it equals y.
ex. 5x+2y=y
Thank you so much for all your help!
Yours,
Rosie

ms.bearse said...

Question 4 from page 304 deals with changing equations into y=mx+b form

if we have 3y-4x=-12 the goal is to get y all by itself on one side of the equation. We will first isolate the term that has y in it. Then we will isolate y itself.

3y-4x+4x=-12+4x (adding 4x to each side)
3y=-12+4x (next step divide each term by 3)
3y/3=-12/3+4x/3 (simplify next)
y=-4+(4/3)x (next step make it y=mx+b....we really have y=b+mx right now, so it is not a big change)
y=(4/3)x-4 is the final answer.

From here we can tell that the slope (la pente) is m=4/3, and the y intercept (l'ordonnée à l'origine) is b=-4. To find the x intercept (abscisse à l'origine) we need to understand that the line will cross the x axis when y=0. So, we will replace y in our y=mx+b equation with 0, and solve for x
y=(4/3)x-4
0=(4/3)x-4
0+4=(4/3)x-4+4 (add 4 to each side)
4=(4/3)x (next multiply by 3 on both sides)
3(4)=3(4/3)x
12=4x (next divide by 4 on both sides)
12/4=4x/4
3=x
the line passes through the point (3,0).

Rosemary said...

Dear Mme. Bearse,
Your answer to my last question was very useful!!! Thank you so much for helping me!
Rosie

ms.bearse said...

You are welcome! I'm glad that you are making use of this forum. Feel free to let others know that it is useful. People will be able to benefit from seeing your questions, and the answers to them, don't you think?

Have a good weekend.

Rosemary said...

I agree!! I will pass the word amoung the class about this amazing website!!! Thank you!!! But first I want to ask a few questions, please.

I need some help in understanding the math for the test. I understand most of it, and I'm making my way through the revision test but I got stuck on questions 3 and 4. I am not sure how to find the point of intersection. I am also unsure about finding the value of n in the following question:
3/2m - 24 = 6/5n

Thank you so much for all your help!!!
I really appreciate it!
Rosie

Rosie said...

Dear Mme. Bearse,
Sorry to trouble you, again but I am really having trouble in Math. I think I have the risk of doing really badly on the test. I've been trying to work it out but it doesn't make sense to me. I really need help. I couldn’t attend the Math Party at lunch because I was participating in a mandatory meeting for the December 6 assembly. Please, would it be possible for me to meet you somewhere before classes start to ask you/ work through a few questions and to boost my confidence? I would greatly appreciate it if you could.
Thanks,
Rosie

ms.bearse said...

Hi Rosemary, Sorry this is late, but I was at choir tonight, and I just got home.

Question 3 is one that we'd do graphically.

Step 1: rearrange each equation into the form y=mx+b

Step 2: graph each line
-2 methods: start with the b value on the y axis, and use m (la pente) to find your next points (moving vertically according to the numerator, and horizontally according to the denominator)
-the other method is to find where the line will cross the x axis (abscisse) and the y axis (ordonné)
to find the abscisse, we set y=0, and then calculate the value for x. To find the ordonné, we set x=0, and calculate the value for y.

Example: question 3 from page 337
equation A: 3x+y-1=0
equation B: 2x=y-6
rearrange equation A
3x-3x+y-1=0-3x
y-1+1=-3x+1
y=-3x+1
we know that this line will pass by the y axis at +1
it will pass the x axis at...
0=-3x+1
0+3x=-3x+3x+1
3x÷3=1÷3
x=0.33333
so now we have 2 points that the line passes through (0,1) and (0.3333,0)

Equation B:
2x=y-6
2x+6=y-6+6
y=2x+6
this line passes through the y axis at +6, and the x axis at...
0=2x+6
0-6=2x+6-6
-6÷2=2x÷2
-3=x
this line goes through the points (0,6) and (-3,0)
Once you draw the two lines on the same axes, you can determine the point of intersection between these lines.

As for question 4a (the one you described)...
(3/2)m-24=(6/5)n
we need to first get rid of the denominators. I am going to multiply everything by 2 and everything by 5, because those are the denominators in the question. Since I am multiplying by 2 and 5, it's the same thing as multiplying everything by 10.
10(3/2)m-10(24)=10(6/5)n
I multiply 10 by each numerator
(30/2)m-240=(60/5)n
now I will simplify these fractions...they should turn into whole numbers after this step.
15m-240=12n
now they want to know the value of n, so I need to get n all by itself on one side of the equation. We are almost there...we need to divide by 12.
12n÷12=(15/12)m-(240/12)
now I simplify the fractions (again!)
n=(5/4)m-20

I'll be in the class right at the bell. If you get there early I'll talk you through this again. I know you can do well. Just be sure to be calm, and work step by step through the questions.

P.S. You did well at the assembly!

Anonymous said...

Hello Madame Bearse,

I just wanted to say that you are a great teacher; you really helped me stay calm during the test!!! Thank you for all your help and advice!

The assembly was a difficult one and it really shocked me how disrespectful some people were. The audience quieted down near the end though. I think many of them were embarrassed since the topic was very intense.

I had my tutoring session today! It went very well. We're working on French reading and speaking at the moment.
Thank you, again for all your help!!!
Rosie
P.S. Can't wait for Num3ers

Vicky said...

Hello Mme Bearse-
its vicky and im back from jamaica.. ive been trying to do these question throughout 5.8-5.9 but i really am having big troubles i looked on your devoirs and the test is tuesday and wednesday and all chapter 5 quiz on thursday... im having alot of trouble becuase I am not having a lesson explaining this.. im scared that if i fall behind I fall behind the test will be a nightmare, I asked some people on msn about math and they said they had no idea what I was talking about,should I wait to get help or what? I have finished all of my other courses homework expect math? and what is eqao? is it a math test? I'm going to fail?

your troubled student,
vicky

ms.bearse said...

Vicky, don't worry, be happy! (like in Jamaica) :)

Welcome back, I hope that your trip was great fun.

I will go over what you need to know with you before you write the test. I want to make sure you understand it all. How is Wednesday at lunch for a math party?

EQAO is the provincial test, it is math, and it doesn't count towards your grade in the course. We will have time to practice before the test comes.

Tomorrow you can get caught up on what we did today (chapter 6, angles and triangles). I don't want you getting behind on the new stuff because you are still catching up on the old stuff.

I'll be putting notes up shortly.
I've gotten a little bit behind!

Don't be troubled, ok? We'll work through all of this stuff together.

Rosie said...

Dear Mme. Bearse,
I tried to send you a message but I think I forgot to send it so here it is again:
I have been trying to do the Frontenac Examen Final but I have been having difficulties understanding some questions. I don't understand some words they use like orthocentre and it is making me rather worried for the real exam. I was wondering if we could have a math party soon. I think my confidence will increase drastically if I could finish the mock exam! Thanks for your help!
Rosie

Ms.Bearse said...

Don't worry! The math curriculum has changed...we no longer need to know the centers of triangles. We are also not quite finished the course yet, so we will be spending more time doing volume and surface area of 3D shapes.

Bring what you have been working on, and I'll help you Monday at lunch. I'll be able to tell you what questions you need to worry about.

Keep working hard!

Anonymous said...

Dear Mme. Bearse,
Please excuse me for my forgetfulness but I seem to have forgotten or most likely lost, my formula sheet. I was wondering if you could put one on the website or if I could get one from you tomorrow.
Thanks,
Rosie

P.S. Thank you for putting the review sheet up on the website! I am going to use it as a checklist for the exam!

Ms.Bearse said...

The fomula sheet is now available.
I'm glad you are working hard on your review already!
I posted the EQAO sample test that we started also. There are multiple choice questions in the EQAO test too.

Rosie said...

Dear Mme. Bearse,
Sorry to bother you but I was wondering if for the EQAO tomorrow, are we just filling out survey questions or doing the actual math?
Thanks,
Rosie

Ms.Bearse said...

Come prepared to do the test. I haven't seen the booklets, but as I recall, the first day is a survey. Things change year to year, so I cant be 100% sure.

See ya tomorrow.

Anonymous said...

Hello it's me, again!
Just asking for a bit of math advice. I am having difficulties remembering how to figure out the interception between two equations.
ex. y=2x-3
2y=12x+2

Thanks so much,
Rosie

Anonymous said...

Dear Mme. Bearse,
Sorry to bother you, again but is it possible to have a math party at lunch or after school tomorrow?
I need some help with intersections and some other things too. I think it would really help to get me prepared for the in class exam on Thursday which I am really nervous about!!
Thank you so much,
Rosie

Ms.Bearse said...

The way we do this in grade 9 is by graphing.
make each equation into y=mx+b form, then graph them both on the same set of axes. Then you can read the intersection point directly off the graph.

Ms.Bearse said...

Math party every day this week at lunch. :)
I'll help you with your intersection problems, and we'll go over the other exploration that we did.

Anonymous said...

Dear Mme. Bearse,

I have two last questions (I think!) before the end of the semester. I can't remember how to find the rise and the run to determine the pente of a graph. I also am having difficulties with the question 10 d on the English Frontenac Math exam.

Thank you so much for all your help this semester and I'll see you bright and early tomorrow morning for the exam!! Yikes!
Thanks,
Rosie

Ms.Bearse said...

To find the slope (pente) of a line you find two places where the line crosses exactly over the grid lines of the graph paper. Write the coordinate points of these two places. One point will be (x1,y1) and the other will be (x2,y2). Then you use these values for calculating the slope
m=(y2-y1)÷(x2-x1)

I don't know which english exam you are working from...I cant seem to find one that has a part d question for 10. If you are still having trouble, let me know which exam you are using (what year the exam is). I'll try to help.

Get a good sleep. You will do fine tomorrow.