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3. 1. multiply integers
2. be observant of the signs when
multiplying integers

5. follows the same
algorithm when
the only difference is when
you’re dealing with .

6. 4 × 3 = 12
We normally use this multiplication symbol to imply
multiplication.

7. 4 3 =× 12
But in algebra we don’t use multiplication symbol
anymore instead we use a to imply multiplication.

8. 4 3 12
But then again, the dot is seldom used in manipulating
algebraic or polynomial expressions. Instead, we most of
the time use on implying multiplication.
( =)

9. follows the same
algorithm when
the only difference is when
you’re dealing with .

10. Rules in Multiplying Integers
1. When you multiply two numbers with the , the
product is .
+ + = (+) − − = +
2. When you multiply two numbers with , the
product is .
+ − = (−) − + = (−)
3. Any multiplied by 0 gives a product of .

11. Example 1:
5 (−7) 35
1. Multiply. 2. Check the sign.
Multiply.
=

12. Example 1:
5 (−7) 35
1. Multiply. 2. Check the sign.
Check the sign.
=
UNLIKE signs.
+

13. Example 1:
5 (−7) 35
1. Multiply. 2. Check the sign.
Check the sign.
= −
UNLIKE signs.

14. Example 1:
5 (−7) 35
1. Multiply. 2. Check the sign.
= −

15. Example 2:
3 (−9) 27
1. Multiply. 2. Check the sign.
Multiply.
=

16. Example 2:
3 (−9) 27
1. Multiply. 2. Check the sign.
Check the sign.
=
UNLIKE signs.
+

17. Example 2:
3 (−9) 27
1. Multiply. 2. Check the sign.
Check the sign.
= −
UNLIKE signs.

18. Example 2:
3 (−9) 27
1. Multiply. 2. Check the sign.
= −

19. Example 3:
(−5)(2) 10
1. Multiply. 2. Check the sign.
Multiply.
=

20. Example 3:
(−5)(2) 10
1. Multiply. 2. Check the sign.
=
Check the sign.
UNLIKE signs.
−

21. Example 3:
(−5)(2) 10
1. Multiply. 2. Check the sign.
= −

22. Example 4:
(−9)(7) 63
1. Multiply. 2. Check the sign.
Multiply.
=

23. Example 4:
(−9)(7) 63
1. Multiply. 2. Check the sign.
=
Check the sign.
UNLIKE signs.
−

24. Example 4:
(−9)(7) 63
1. Multiply. 2. Check the sign.
= −

25. Example 4:
3 (6) 18
1. Multiply. 2. Check the sign.
Multiply.
=

26. Example 4:
3 (6) 18
1. Multiply. 2. Check the sign.
=
Check the sign.
LIKE signs.
+

27. Example 4:
3 (6) 18
1. Multiply. 2. Check the sign.
=

28. Example 5:
7 (7) 49
1. Multiply. 2. Check the sign.
Multiply.
=

29. Example 5:
7 (7) 49
1. Multiply. 2. Check the sign.
=
Check the sign.
LIKE signs.
+

30. Example 5:
7 (7) 49
1. Multiply. 2. Check the sign.
=

31. Example 6:
−2 (−3) 6
1. Multiply. 2. Check the sign.
Multiply.
=

32. Example 6:
−2 (−3) 6
1. Multiply. 2. Check the sign.
=
Check the sign.
LIKE signs.

33. Example 6:
−2 (−3) 6
1. Multiply. 2. Check the sign.
=

34. Multiply.Zero factor.
Example 7:
−192 (0) 0
1. Multiply. 2. Check the sign.
=

35. Got
questions?

37. Multiply the following integers.
1. 9(2)
2. −2(−5)
3. 8(−5)
4. −4(−9)
5. −8(1)
6. (−5)(−6)
7. −7(−8)
8. 0(−4)
9. −1(−49)
10.(2)(−2)
= 18
= 10
= −40
= 36
= −8
= 30
= 56
= 0
= 49
= −4
1. Multiply. 2. Check the sign.

38. Got
questions?

40. Rule for a Product with No Zero Factors
1. If the number of negative factors is , the
product is .
2. If the number of negative factors is , the
product is .

41. Multiply.
Example 1:
−2 −3 (5) 30=
2 36(5)
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

42. Count the number of
.
Example 1:
−2 −3 (5) 30=
Two so it is that means the sign of the
product is .
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

43. Example 1:
−2 −3 (5) 30=
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

44. Multiply.
Example 2:
−6 −2 (−5)(−8) 480=
6 212 (5)60 (8)
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

45. Example 2:
−6 −2 (−5)(−8) 480=
Count the number of
.
Four so it is that means the sign of the
product is .
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

46. Example 2:
−6 −2 (−5)(−8) 480=
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

47. Multiply.
Example 3:
−1 −2 (−3)(−4)(−5) 120=
1 22 (3)6 (4)24 (5)
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

48. Example 3:
−1 −2 (−3)(−4)(−5) 120=
Count the number of
.
Five so it is that means the sign of the
product is .
−
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

49. Example 3:
−1 −2 (−3)(−4)(−5) 120= −
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.

50. Got
questions?

52. Multiply the following integers.
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.
1. −2 2 (−2)(−2)
2. −52 62 (−13)(0)(10)(−22)
3. −3 −1 (−1)(−6)
2. −2 1 (−10)(−1)(−1)(5)
3. [ −2 3 ](−4)(10)

53. Answers!

54. Multiply the following integers.
Rule for a Product with No Zero Factors
1. If the number of negative factors is , the product is .
2. If the number of negative factors is , the product is .
1. Multiply
2. Check the sign.
1. −2 2 (−2)(−2)
2. −52 62 (−13)(0)(10)(−22)
= −16
= 0
3. −3 −1 (−1)(−6) = 18
2. −2 1 (−10)(−1)(−1)(5) = 100
3. [ −2 3 ](−4)(10) = 240

55. Got
questions?

56. E-Math 7
Practice and Application
Test I
Test III
Page 44