Review Add Matrices Subtract Matrices

Objective: students will demonstrate they can apply the rules of multiplication to numerical and algebraic expressions 2.5 Multiplying Numbers

Multiplying Integers Multiplication Rules: Number x 0 = 0 Pos. x Pos. = Pos. Ex: 3 x 4 =12 Neg. x Neg. = Pos. -4 x -5 = 20 Neg. x Pos. = Neg. -4 x 8 = -32 Number x 0 = 0 Ex: 8 x 0 = 0 Number x 1 = number Ex: 9 x 1 = 9

Multiplication Properties Commutative Prop. of Multiplication AB = BA 2(4) = 4(2) Associative Prop. of Multiplication (AB)C = A(BC) (2 x 1) x 4 = 2 x (1 x 4)

Identity Properties Multiplication Property of zero Property of opposites a + -1 = -a 7 + -1 = -7 Identity Property of Multiplication a x 1 = a 7 x 1 = 7 Multiplication Property of zero a x 0 = 0 6 x 0 = 0

Identify the Property Used-t/s -8 x 0 = 0 2 (-49) = (-49)2 y2 x -1 = -y2 2(pq) = (2p) q 3 (xy) = (3x) y -8 x 0 = 0 2x3 = 3x2 8 x 1 = 8

Teacher Examples 7 x -6 -11 x -9 -8 x -7 9 x 3

Student Examples 10 x -11 -6 x -9 -11 x -8 -7 x 4 0 x 60 -6 x -8

Multiplying with variables NOTE: same base add exponents! 3x(2y) 3x(5)6x -5h(6h) 4(-3n)

Multiplying with Variables -st 8j(-2) 3(x)2x -2(-8x) 9a(-2b)a 4x(2x) -3x(2y)4z

Story Problems ELEVATORS An elevator takes passengers from the ground floor down to an underground parking garage. Where will the elevator be in relation to the ground floor after 7 seconds if it travels at a rate of 5 feet per second? TEMPERATURE The temperature dropped 5°F every hour for the last 10 hours. What is the total change in temperature?

Wrap up Questions/Comments Hw: text pg. 96, #’s: 16-58 evens, 62