You can put this solution on YOUR website! (9b+1)^2=
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= (9b+1)(9b+1)
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= 81b^2 + 9b + 9b + 1
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= 81b^2 + 18b + 1
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Cheers,
Stan H.
Learn this rule: (A + B)² = A² + 2AB + B²
In your problem
(9b + 1)²
comparing that with the above substitute 9b for A and 1 for B
(9b + 1)² = (9b)² + 2(9b)(1) + (1)²
= 81b² + 18b + 1
Edwin