1. 1.1 Variable in Algebra 1.2 Exponents & Powers

2. A variable expression contains: 1) one or more numbers or variables, and 2) one or more operations. Examples: x - 3 3 2n

3. In expressions, there are many different ways to write multiplication. 1)ab 2)a b 3)a(b) or (a)b 4)(a)(b) 5)a x b We are not going to use the multiplication symbol any more. Why?

4. Division, on the other hand, is written as: 1) 2) x ÷ 3

5. Here are some phrases you may have listed. The terms with * are ones that are often used.

6. Write an algebraic expression for 1) m increased by 5. m + 5 2) 7 times the product of x and t. 7xt or 7(x)(t) or 7 x t

7. 3) 11 less than 4 times a number. 4n - 11 4) two more than 6 times a number. 6n + 2 5) the quotient of a number and 12.

8. Which of the following expressions represents 7 times a number decreased by 13? 1.7x + 13 2.7x - 13 3.13 - 7x 4.13 + 7x Answer Now

9. Which one of the following expressions represents 28 less than three times a number? 1.28 - 3x 2.3x - 28 3.28 + 3x 4.3x + 28 Answer Now

10. Write a verbal expression for: 1) 8 + a. The ratio of m to r Do you have a different way of writing these? The sum of 8 and a 2)

11. Which of the following verbal expressions represents 2x + 9? Answer Now 1.9 increased by twice a number 2.a number increased by nine 3.twice a number decreased by 9 4.9 less than twice a number

12. Which of the following expressions represents the sum of 16 and five times a number? Answer Now 1.5x - 16 2.16x + 5 3.16 + 5x 4.16 - 5x

13. base and 3 is called the exponent or power. 10 3 means 10 10 10 10 3 = 1000 When looking at the expression 10 3, 10 is called the

14. How is it said? 2 1 Two to the first power2 Two to the second power or two squared 2323 Two to the third power or two cubed 2n 7 Two times n to the seventh power

15. Which of the following verbal expressions represents x 2 + 2x? Answer Now 1.the sum of a number squared and twice a number 2.the sum of a number and twice the number 3.twice a number less than the number squared 4.the sum of a number and twice the number squared

16. Which of the following expressions represents four less than the cube of a number? Answer Now 1.4 – x 3 2.4 – 3x 3.3x – 4 4.x 3 – 4

17. Evaluate. 2 1 22 2 2 = 4 2323 2 2 2 = 8 2n 7 We can’t evaluate because we don’t know what n equals to!!

18. Is 3 5 the same as 5 3 ? Evaluate each and find out! 3 5 = 3 3 3 3 3 = 243 5 3 = 5 5 5 = 125 243 ≠ 125 They are not the same!

19. Open your Textbooks Page 12 # 20-30 even