Question

$30 ^{2} - 29 ^{2} \\ 57 {}^{2} - 56 {}^{2}$

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Answer 1

Формула: $a^2-b^2=(a-b)(a+b)$

$30^2-29^2=(30-29)(30+29)=1\cdot 59=59$

$57^2-56^2=(57-56)(57+56)=1\cdot 113=113$