Answer:
- not possible: 1, 2, 4, 5, 8, 11
- possible: all others
Step-by-step explanation:
Obviously, all multiples of 3 and 7 can be paid.
1 cent can be added by adding a 7-cent stamp and taking away two 3-cent stamps. 2 cents can be added by adding three 3-cent stamps and taking away one 7-cent stamp. Hence any value more than 7 +2(3) = 13 cents can always be accommodated.
Amounts that are impossible:
1, 2, 4, 5, 8, 11 cents
All other positive integer amounts are possible.
<h3>
Answer:</h3>

<h3>
Explanation:</h3>
Change
so that is has a common denominator. 
Make an equation. 
Add. 
Add. 
Divide both sides by 2. 
Convert to a mixed number. 
Answer: x=10 7/8
Step-by-step explanation:
Subtract 3/4 from both sides. Multiply both sides by 3. Divide both sides by 2 (basically just isolate x on one side of the equal sign).
Reeeee.............tooooooooo
Answer:
- Both expressions should be evaluated with two different values. If for each substituted value, the final values of the expressions are the same, then the two expressions must be equivalent.
Step-by-step explanation:
<u>Given expressions</u>
- 4x - x + 5 = 3x + 5
- 8 - 3x - 3 = -3x + 5
Compared, we see the expressions are different as 3x and -3x have different coefficient
<u>Answer options</u>
Both expressions should be evaluated with one value. If the final values of the expressions are both positive, then the two expressions must be equivalent.
- Incorrect. Positive outcome doesn't mean equivalent
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Both expressions should be evaluated with one value. If the final values of the expressions are the same, then the two expressions must be equivalent.
- Incorrect. There are 2 values- variable and constant
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Both expressions should be evaluated with two different values. If for each substituted value, the final values of the expressions are positive, then the two expressions must be equivalent.
- Incorrect. Positive outcome doesn't mean equivalent.
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Both expressions should be evaluated with two different values. If for each substituted value, the final values of the expressions are the same, then the two expressions must be equivalent.