Math 7-44: Growing Post #3

Friday, June 02, 2006

Growing Post #3

Questions due Tuesday May 30th (Created by Boeun)

#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.

- They all have variable, starting point, and change. The letter of the variable doesn't matter. It can be A B C D E F G… any alphabets we can use. What matter is that does the variable in an algebraic equation or expression is given. In an equation the value of the variable is already given to balance each side of the equal sign.

Example of an expression is 5n x 2 and example of an equation is this. 5 x 2 = 10

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

- Variable means unknown number. We don’t know the number that is unknown so we are using alphabet to make expression so we can solve it and get variable

#3 Solve N
- One circle is equal to 1. All 9 circles are equal to 9. Two squares are equal

to 4. One triangle is equal to 5 so 9-4= 5.
- 6 squares are equal to 12 so 12 + 5 + 5= 22
- 22 divided by 2 is 11, then N is equal to 11

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

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

3n + 4n + 7 = 2n + 12

7n + 7 = 2n +12

7n + 7 = 2n + 12

- 2n -2n

5n + 7 = 12

- 7 - 7

5n = 5

5 ÷ 5 = 1

n = 5

b) 8n – (4+9) = 11

8n – (4+9) = 11

8n – 13 = 11

+ 13 + 13

8n = 24

24 ÷ 8 = 3

n = 3

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

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

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

12n + 8 = 4n + 40

- 4n -8 -4n -8

8n = 32

32 ÷ 8 = 4

n = 4

#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, who will be the first to make it to the finish line 2000m away?