a)

\(A = 2010 \cdot 2010 = 201 0^{2} .\)

\(B = 2009 \cdot 2011 = \left(\right. 2010 - 1 \left.\right) \left(\right. 2010 + 1 \left.\right) = 201 0^{2} - 1.\)

=> \(A - B = 201 0^{2} - \left(\right. 201 0^{2} - 1 \left.\right) = 1 > 0.\)

Vậy \(A > B .\)

\(\textbf{b})\)

\(A = 234234 \cdot 233.\)

\(B = 233233 \cdot 234.\)

Ta có \(A - B = 234234 \cdot 233 - 233233 \cdot 234\)

\(= 234234 \cdot 233 - 233233 \cdot 233 - 233233\)

\(= \left(\right. 234234 - 233233 \left.\right) \cdot 233 - 233233\)

\(= 1001 \cdot 233 - 233233\)

\(= 233233 - 233233\)

$=0.

Vậy $A=B.$$=0.$

Vậy

\(A = B .\)

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