Question

ДАЮ 100 БАЛЛОВ 7 класс АЛГЕБРА

Answer 1

             $\boxed{\ (a\pm b)^2=a^2\pm 2ab+b^2}$

$1)\ \ (4x+7)^2=16x^2+56x+49$    тождество  №3

$2)\ \ (b+1)^2=x^2+2x+1\\\\(3x-1)^2=9x^2-6x+1\\\\(3x+7y)^2=9x^2+42xy+49y^2\\\\(5-ab)^2=25-10ab+a^2b^2\\\\\Big(\dfrac{1}{5}\, a+5b\Big)^2=\dfrac{1}{25}\, a^2+2ab+25b^2\\\\(3a^2-c^4)^2=9a^4-6a^2c^4+c^8\\\\\Big(\dfrac{1}{3}\, x^4+0,9y^3\Big)=\dfrac{1}{9}\, x^8+\dfrac{3}{5}\, x^4y^3+0,81y^6\\\\\Big(\dfrac{9}{7}\, ab-\dfrac{7}{8}\, c\Big)^2=\dfrac{81}{49}\, a^2b^2-\dfrac{9}{4}\, abc+\dfrac{49}{64}\, c^2$