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math fun to learn and easy to teach for grades
1 through 9. |
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Find
at which step of the following proof, it becomes
false. And give the reason. |
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Does
2 = 1 ? |
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| 1. |
A
= B |
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Add A to
both sides |
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2. |
A
+ A = A + B |
| 3. |
2A
= A + B |
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Subtract
2B from both sides |
| 4. |
2A
- 2B = A + B - 2B |
| 5. |
2A
- 2B = A - B |
| 6. |
2(A-B)
= A - B |
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Divide
both sides by (A-B) |
| 7. |
2
= 1 |
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| 2
can't equal 1! What's wrong with this problem? |
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