SOLUTION: Please answer these questions i find it difficult to understand.. 1) Explain why can x be zero in x/3(x over 3) but not on 3/x(3 over x). Why division by zero is undefined whil

Question 408094: Please answer these questions i find it difficult to understand..
1) Explain why can x be zero in x/3(x over 3) but not on 3/x(3 over x). Why division by zero is undefined while division of zero by a non-zero number is defined?
2) Explain why the rational expression 2x+1 over x+1 is not equal to 2.
3) If ab=10 and a+b=7, find 1/a+1/b.

Thank you in advance and hoping for your immediate reply.

Answer by richard1234(7193) (Show Source): You can put this solution on YOUR website!
1. Because it's possible to put zero objects into three groups, but it is impossible to put three objects into zero groups (assuming all three objects are distributed).
2. If , then by cross-multiplying, , , contradiction.
3. .
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