Wednesday, May 31, 2006

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.

An algebraic equation is when the variable is given and it's when you have to solve for the variable.
Example -
3 + 2r = 10
3 + 2(1) =
3 + 2 = 5

An algebraic expression is when the variable is chosen as a number.
Example -
4 + 5(2) =
4 + 10 = 14

The difference is the equation has the variable already given and the expression is when the variable is shown as a number.

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.
We use variables in algebra to represent an unknown number. Variables can also help you solve some questions faster. The format should look like this - Start + Change (Variable) =
The variable can be changed (the one in brackets) while you are trying to solve for unknown.

Question #3 Solve for N



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

a) 3n + 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

12n + 8 = 4n + 40

12n - 4n + 8 = 4n + 40 - 4n

8n + 8 = 40

8n + 8 - 8 = 40 - 8

8n = 32

8n/8 = 32/8

n = 4

Question #5 For this question you need to create a T-Chart and a graph to plot your data form 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 bill be faster so your friend gives you a head start of 3 minutes. If you can run 400m per minute, and you friend can bike 700m per minute, who will be the first to make it to the finish line 2000m away?




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2 Comments:

At 7:24 PM, Blogger Mr. Reece said...

Jake this post looks great, but there are two small problems. First it is with algebraic expressions. In both equations and expressions the letter stands for a number, but in an expression can the letter stand for more than one number?

Second problem is with 4c. The answer is not n=3, so check it over again for your mistake.

 
At 1:03 PM, Blogger Mr. Reece said...

Thank you for making some of the modifications. The response to expression vs equation is still a little confusing

Your mark is 29/30

 

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