1. Multiply and Divide Integers
2.3
Multiply and Divide Integers

2. Review -12+8 0-(-9) -7+(-4) 2-(-4) -6-(-9)-(4)+13
Write the sum of y and negative five
True, sometimes true or false:
The difference between a number and its additive inverse is zero
The sum of a negative number and a negative number is a negative number

3. Multiplying Steps for Multiplying Integers
1. Multiply the numbers and ignore their signs
2. If both have the same signs (positive-positive or negative-negative) then the answer is a positive number.
3. If they opposite signs (one negative and one positive) then the answer is negative.

4. Examples
-7(4) = -28
3(-2) = -6
4(5) = 20
(-6)(-1) = 6

5. Properties Multiplicative property of zero A*0 = 0
Multiplicative property of one
a*1 = a
Commutative property
a*b = b*a *3 = 3*2
Associative Property of Multiplication
(a*b)*c = a*(b*c)

6. Division Same rules as multiplication
1. Divide the numbers and ignore their signs
2. If both have the same signs (positive-positive or negative-negative) then the answer is a positive number.
3. If they opposite signs (one negative and one positive) then the answer is negative.

7. Properties Top = numerator Bottom = denominator a / 1 = a 0 / a = 0
Zero cannot be in the denominator
a/0 = undefined
b/a is okay as long as a does not equal 0

8. examples
-2 / -2 = 1
50 / -10 = 5

9. Try it (-38)(51) -1938 -7(-8)(9)(-2) -1008
Is -3 a solution to 12 = -4a
Yes’m
What is zero divided by -17
Zero
84/-6
-14
Is -3 a solution to: -6/y = -2
No!
The daily high temperatures for one week in winter were:
-7, -8, 0, -1, -6, -11, -2 -5

10. 2.3 homework
1 thru 119 EOO
20, 36, 48, 60, 80, 84, 90, 100, 108, 112