Chapter 4-2 Power and Exponents UNIT 2 Chapter 4-2 Power and Exponents

The power is the number that can expressed as an exponent An expression like 2 x 2 x 2 x 2 can be written as a power. A Power has 2 parts, a Base and an Exponent An Exponent shows repeated multiplication The base is the number 4² The exponent tells how many times that is multiplied the base is used as a factor The power is the number that can expressed as an exponent

Exponents How to write and read powers with a positive exponent. 2 ¹ 2 to the first power = 2 2 ² 2 to the second power or 2 squared = 2 • 2 2 ³ 2 to the third power or 2 cubed = 2 • 2 • 2 2 ⁴ 2 to the fourth power or 2 to the fourth = 2 • 2 • 2 • 2 ****Any number raised to the 0 power equals 1! 6 0 = 1 100 0 = 1

Write Each Expression Using Exponents B) (-8) (-8) = (-8) ² C) 7 • X • X• X• Y•Y = 7x³ y²

Evaluate Each Expression Since powers are a form of multiplication, they need to be included in the rules for order of operation. Remember…Orders of Operation: Parenthesis ( ) Exponents Multiply or Divide left to right Add or Subtract left to right

Evaluate Each Expression A) 2 ³ = 2 • 2 • 2 = 8 B) Y ² + 7 if y = 3 (3)² + 7 Replace y with 3 (9) + 7 Simplify the exponent and Add = 16

Let’s Try Some Examples Write each expression using exponents 1)4 • 4 • 4 • 4 • 4 2) 6 3) (-5)(-5)(-5) Evaluate each expression 4) Z² if z = 9 5) X ² • 2², X = 3

Let’s Check Our Answers Write each expression using exponents 1)4 • 4 • 4 • 4 • 4 = 4 4 2) 6 = 6 1 3) (-5)(-5)(-5) = (−5) 3 Evaluate each expression 4) Z² if z = 9 5) X ² • 2², if X=3 (9)² = 81 (3)² • 2 2 9 • 4 = 36