Предмет: Алгебра, автор: Игррь1

решите пожалуйста)))))

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Автор ответа: Arve

А) (3 $\sqrt{112}$ +2 $\sqrt{175}$ )/7 = (3 $\sqrt{4*4*7}$ +2 $\sqrt{5*5*7}$ )/7 = (12 $\sqrt{7}$ +10 $\sqrt{7}$ )/7 = 22 $\sqrt{7}$ /7.
Б) (3 $\sqrt{7}$ - $\sqrt{15}$ )(3 $\sqrt{7}$ + $\sqrt{15}$ ) = 63-15=48.

Автор ответа: leral678l

Я знаю только б)
Там действует формула (a+b)×(a-b)=a^2-b^2

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