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Answer:
- 9x² +6x +1
- 9x² -1
- (3x +1)(3x -1)
Explanation:
The first step seems to be to eliminate parentheses:
9x² +6x +1 -6x -2 = ...
The next step is to collect terms:
9x² -1 = ...
Then this special form is factored:
(3x +1)(3x -1) = ...
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Additional comment
The identity can also be proved by factoring (3x+1) from both terms on the left:
(3x +1)(3x +1 -2) = ...
Then simplify the second factor:
(3x +1)(3x -1) = ...