Seppe's scribepost

Question 18, 2.4 on page 79

18. A frame measures 30 cm by 20 cm. Can you mount a square picture with an area of 500 squared cm in the frame? Explain.

Frame
= 30 x 20

Picture
= 500

So to find the sides of the picture, you have to find the square root of 500 which is 22.36.
One side of the picture is too big for the frame so the answer is no, it can't fit in the frame.

PLEASE COMMENT (IF YOU WANT) TO MAKE MY POST A BETTER ONE :D

Connor's Post for November 9th Question 13

In math class we were all assigned questions and mine was question 13 in section 2.3.

13. The diameter of Pluto is 6/17 the diameter of Mars. Mars is 17/300 the diameter of Saturn.

A) What fraction of the diameter of Saturn is the diameter of Pluto.

Since Pluto is 6/17 of Mars and Mars is 17/300 of Saturn you need to cancel out the 17.
You are left with 6/300 and that is 0.02.
0.02 x 50 = 1
1/50 is the final answer.

B) The diameter of Saturn is 120 000 km. What is the diameter of Pluto?

1/50 = 0.02
120000 x 0.02 = 2400
The diameter of Pluto is 2400km.

Question 17 2.4 by The Most Awesomest Alex

Yeah yeah awesomest isn't a word I know but still, I'm awesome so I put that, but anyways to the question, I would've done this sooner but my dad needed to use his computer for work or something so I waited but he's done so I can use it.

Basic things really you just need to know how to find area the steps at least, and how to multiply simple.

17. Some parks contain fenced gardens. Suppose that it costs $80 to build each metre of fence, including materials and labour.

A) How much does it cost to enclose a square with an area of 120 squared metres? Express your answer to the nearest dollar.

Well first of all you have to isolate how many metres are in each side of the fence, you do that by square rooting(?) the area to get a side length, you should get about 10.95 then you have to multiply that by 4 because of each side so it equals, 43.816. Haha I last step multiply that by 80 because you need to find out the price of the work and materials put in so 43.816x80=3505.28 but you need to round it to the nearest tenth so it's 3505.3.
It will cost $3505.30 to enclose the area.

B) Predict whether the total cost of enclosing two squares with an area of 60 squared metres each is the same as your answer to part a).

Well I think it wouldn't because even if the 2 squares shared a fence you would still need to add that to the total amount of fence needed, because everything else would be similar if not the same (it's a guess).

C) Test your prediction from part b) and describe your findings.

Gah more math, and I thought we were supposed to be lazy, geez.
Well anyways same process as A) so 60 squared metres square rooted(?) is 7.746 that multiplied by 4 is 30.984. Multiply 30.984 by 2 because there is 2 squares and you get 61.968, now there's 2 ways of going from here assume they don't share a fence, and assume the do, for the sake of having all the proof, I'm doing both, your welcome.
61.968x80=4957.44 (4957.4 rounded)
61.968-7.746(once side of fence)=54.222
54.222x80=4337.76 (4337.8 rounded)
So it would either cost $4957.40 or $4337.80 which means I was correct for the main part of my prediction was correct in saying it would cost more.

There FINISH HA done.
Any questions just comment.
Again no colour sorry I'm just really lazy.

Jerick's Math Blog Post for 2.3 , November 14, 2010

Hey everyone ! This is my blog post for the question I was assigned for math
the question is ..

24. Can the sum of two rational numbers be less than both of the rational numbers? Explain using examples in fraction form .

The answer would be, yes the sum of two rational numbers can be less than both of the rational numbers, that is ,if the sum is negative.

Example:
(-3/4) + (-2/3 ) = -17/12 or -1 5/12

I have to admit, this question kind of confused me, so please, if anyone can explain it to me, I would gladly appreciate it
and
If you have any other examples, please feel free to put it as a comment
Thank You for Reading My Post

Mary Jane's Scribepost for November 9, 2010

For today's math class, Mr. Backe assigned each of us a question to do for a scribe post. I was chosen to do number 22 of chapter 2.4 on page 80.


The hypotenuse of an isosceles right triangle has a length of 20 cm. What is the length of each leg of the triangle? Provide your answer to the nearest tenth of a centimetre.

Isosceles Right Triangle: a triangle with two equal side lengths.




Conclusion:


The triangle had a hypotenuse of 20 cm and so what I did was I used the formula c (squared) = a (squared) + a (squared) to get the length of a. Then I took 20 (squared) or 400 and divided it by 2 to get a (squared) by itself. So now we're left with square root of 200 = the square root of a (squared) to get a by itself. We then end up with 14.1 cm (rounded to the nearest tenths place) as the length of a.




Thanks for reading my scribe post. Please feel free to tell me what I did wrong and correct me when you are commenting.

Question 15

Hey its me Alex, I finally get to do my posts because I got my Internet security back on my computer.
This question wasn't to hard just basic multiplication of decimals.
Now on to the question.

15) In dry air, the temperature decreases by about 0.65 degrees Celsius for each 100-m increase in altitude.

A)The temperature in Red Deer, Alberta, is 10 degrees Celsius. What is the temperature outside an aircraft 2.8 km above the city?

Okay to solve this all you really need to do is multiply 0.65 by 28 because in 2.8km there is 28 groups of 100m.
o.65x28= 18.2
Then you subtract 18.2 from 10 to get -8.2
So the temperature outside the aircraft is -8.2 degrees Celsius.

B) The temperature outside and aircraft 1600m above Red Deer is -8.5 degrees Celsius. What is the temperature in the city below?

This is basically the same process just reversed instead of subtracting you add, so 0.65x16=10.4
then you add 10.4 to -8.2 to get 2.2.
The temperature in Red Deer is 2.2 degrees Celsius.

Well as a famous pig said Thats all Folks.
Comment if you don't get what I did.
The reason I don't have colour is for the people who know me, I'm lazy end of story.

Question 15