Problem 17 of 35alg-017
For , which of the following expressions is equivalent to ?
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Solution walkthrough1:37
- The top, , is a square minus a square, because . Picture it as an area.
- Move one piece and the leftover area becomes a rectangle: .
- Factor the bottom too. Both and are multiples of , so .
- Cancel the shared factor , which is not because . What is left is .
- Traps: keeping instead of , losing the , or moving the to the top.