The inequality properties allow us to divide both sides by 3.

y ⋅ 3 / 3 = y

and

21 / 3 = 7

so

y < 7

Quiz (1 point)

• 1 / 3 > 0
• 21 ⋅ (1 / 3) = 7
• 3 ⋅ (1 / 3) = 1
• (a ⋅ b) ⋅ c = a ⋅ (b ⋅ c)

• if the following are true:

  • a < b
  • c > 0

  then a ⋅ c < b ⋅ c

• if the following are true:

  • a < b
  • a = c

  then c < b

• if a = b, then c ⋅ a = c ⋅ b

• if a = b ⋅ 1, then a = b

• if the following are true:

  • a < b
  • a = x
  • b = y

  then x < y

Please write your proof in the table below. Each row should contain one claim. The last claim is the statement that you are trying to prove.

Step	Claim	Reason (optional)	Error Message (if any)
1
2
3
4
5
6
7
8
9
10

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