Tuesday, May 30, 2006

»» charmaine's growing post # 3

Question # 1 : What is the difference between an algebraic expression and an equation (hint: One contains this and the other doesn't)? Give an example of both an expression and an equation.

In Algebra Expression is when the variable is a number and given and in Algebra Equation, the variable is given as a letter. It's when you try to solve for the variable.


Example:

Algebraic Expression
8 + 2 (3)
8 + 6 = 14
Equation
8 + 2(a)
8 + 2(3)
8 + 6 = 14

Question # 2 : What is a variable and why do we use one in algebra?

A variable is an unknown quantity that we are trying to solve for. It is also represented by a letter. We use variables so we can find what the letter stands for.

Question # 3 : Solve for N





How to solve this:
- First, you subtract 9 by 4 because the two squares are equal to 4. So you'll get 5 as the answer. So now you know what the triangle is equal to. Now, add 12 and 10 together because there's 5 squares and two triangles. 2 + 2 + 2 + 2 + 2+ 5 + 5 = 22. Last is, divide 22 by 2. 2 because there's two N's. the answer is - 11

Question # 4 : Solve the following equations. Show all of the steps that are needed.

a.) 3. + 4n + 7 = 2n + 12

7n + 7 = 2n + 12

7n - 2n + 7 = 2n - 2n = 12

5n + 7 = 12

5n + 7 - 7 = 12 - 7

5n = 5

5n/5 = 5/5

n = 1


b.) 8n - (4 + 9) = 11

8n - 13 = 11

8n - 13 + 13 = 11 + 13

8n = 24

8n/8 = 24/8

1n = 3

n = 3


c.) (8 - 3)n + 7n + 8 = 4n + 40

5n + 7n + 8 = 4n + 40

5n + 7n + 8 - 8 = 4n + 40 - 40

5n + 7n = 4n

12n = 4n

12 = 4n

12/4 = 4n/4

3 = n

Question # 5 : For this question you need to create a T-chart and a graph to plot your data from this question onto.

You are having a race against your friend, except you are on foot and he is on his bike. You both know that if you are on a bike you will be faster so your friend gives you a head start of 3 minute. If you can run 400m per minute, and your friend can bike 700m per minute, who will be the first to make it to the finish line 2000m away?


YOU will be the first one to finish the race (:




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3 Comments:

At 7:34 PM, Blogger Mr. Reece said...

So far it looks great. I just think that you need a bit more clarification between an expression and an equation. remember that an expression we can chose what the value of the variable is ie n = 5 or 10 or 2200 etc. For an equation we are solving for a single value for the variable.

 
At 9:15 PM, Blogger   maaayne said...

hey mr.reece ! , i'm now completed my growing post.. i made some corrections too.

 
At 1:37 PM, Blogger Mr. Reece said...

you have a problem with 3c. You still didn't get the difference between an expression and equation. An expression would be 3 +2b there is no = sign in an expression as the value of b can be anything. For an equation it would be 3 + 2c =9, therefore c =3. There is equality, so the variable c can have only one answer. Your mark is 25/30

 

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