Question

Срочно нужна помощь

Answer 1

$4)(p-2c)^2+3p^2=p^2-4pc+4c^2+3p^2=4p^2-4pc+4c^2\\\\5)81x^2-(9x+7y)^2=81x^2-(81x^2+126xy+49y^2)=81x^2-81x^2-126xy-49y^2=-126xy-49y^2\\\\6)x^2+(5x-3)^2=x^2+25x^2-30x+9=26x^2-30x+9$

Answer 2

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