Дополнения к главе 2. Задание 627. «Алгебра. 7 класс. Учебник для общеобразовательных организаций» АЛГЕБРА 7 ГДЗ Задание 627

    Задание 627

    Сократите дробь:

      • \({\largeа)}\ \frac{x^3-x^2+x+3}{x^2-2x+3};\)
      • \({\largeб)}\ \frac{x^3+x^2+3x-5}{x^2+2x+5};\)
      • \({\largeв)}\ \frac{x^3-1}{x^3+2x^2+2x+1};\)
      • \({\largeг)}\ \frac{x^3+8}{x^3-4x^2+8x-8}.\)

    Источник заимствования: Алгебра. 7 класс. Учебник для общеобразовательных организаций / – Просвещение, 2013. – 167 c. ISBN 978-5-09-027739-6
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    Решение:

      • \({\largeа)}\ \frac{x^3-x^2+x+3}{x^2-2x+3}=\frac{ (x+1)(x^2-2x+3)}{x^2-2x+3}=x+1\)

      • \(\begin{array}{l}\begin{array}{r}-\begin{array}{l}x^3-\phantom{0}x^2+\phantom{0}x+3\\x^3-2x^2+3x\\\hline\end{array}\begin{array}{|l}x^2-2x+3\\\hline{x}+1\end{array}\\\end{array}\\\phantom{\ 00000}\begin{array}{r}-\begin{array}{r}x^2-2x+3\\x^2-2x+3\\\hline\end{array}\end{array}\\\phantom{0000000000000000}\begin{array}{r}0\end{array}\end{array}\)

      • \({\largeб)}\ \frac{x^3+x^2+3x-5}{x^2+2x+5}=\frac{ (x-1)(x^2+2x+5)}{x^2+2x+5}=x-1\)

      • \(\begin{array}{l}\begin{array}{r}-\begin{array}{l}x^3+\phantom{0}x^2+3x-5\\x^3+2x^2+5x\\\hline\end{array}\begin{array}{|l}x^2+2x+5\\\hline{x}-1\end{array}\\\end{array}\\\phantom{0000}\begin{array}{r}-\begin{array}{r}{-}x^2-2x-5\\{-}x^2-2x-5\\\hline\end{array}\end{array}\\\phantom{0000000000000000}\begin{array}{r}0\end{array}\end{array}\)

      • \({\largeв)}\ \frac{x^3-1}{x^3+2x^2+2x+1}=\frac{ (x-1)(x^2+x+1)}{x^3+2x^2+2x+1}=\frac{ (x-1)(x^2+x+1)}{ (x+1)(x^2+x+1)}=\frac{x-1}{x+1}\)

      • \(\begin{array}{l}\begin{array}{r}-\begin{array}{l}x^3+2x^2+2x+1\\x^3+\phantom{0}x^2+\phantom{0}x\\\hline\end{array}\begin{array}{|l}x^2+x+1\\\hline{x}+1\end{array}\\\end{array}\\\phantom{\ 00000}\begin{array}{r}-\begin{array}{r}x^2+\phantom{0}x+1\\x^2+\phantom{0}x+1\\\hline\end{array}\end{array}\\\phantom{0000000000000000}\begin{array}{r}0\end{array}\end{array}\)

      • \({\largeг)}\ \frac{x^3+8}{x^3-4x^2+8x-8}=\frac{ (x+2)(x^2-2x+4)}{x^3-4x^2+8x-8}=\frac{ (x+2)(x^2-2x+4)}{ (x-2)(x^2-2x+4)}=\frac{x+2}{x-2}\)

      • \(\begin{array}{l}\begin{array}{r}-\begin{array}{l}x^3-4x^2+8x-8\\x^3-2x^2+4x\\\hline\end{array}\begin{array}{|l}x^2-2x+4\\\hline{x}-2\end{array}\\\end{array}\\\phantom{000}\begin{array}{r}-\begin{array}{r}{-}2x^2+4x-8\\{-}2x^2+4x-8\\\hline\end{array}\end{array}\\\phantom{0000000000000000}\begin{array}{r}0\end{array}\end{array}\)