с квадратными уравнениями ( )

ЖаннаLife ЖаннаLife    3   13.04.2020 23:22    1

Ответы
annagj200430 annagj200430  13.10.2020 04:50

#1.

3x^2 + 6x = 0\\3x(x + 2) = 0\\3x = 0; x+2 = 0\\x = 0; x = -2

#2.

-2x^2 + 8x = 0\\-2x(x - 4) = 0\\\\\left[\begin{array}{cc}-2x = 0\\x - 4 = 0\end{array}\right\\\\\left[\begin{array}{cc}x = 0\\x = 4\end{array}\right

#3.

x^2 - 4x = 0\\x (x - 4) = 0\\\\\left[\begin{array}{cc}x = 0\\x - 4 = 0\end{array}\right\\\\\left[\begin{array}{cc}x = 0\\x = 4\end{array}\right

#4.

7x^2 - 14x = 0\\7x(x - 2) = 0\\\\\left[\begin{array}{cc}7x = 0\\x - 2 = 0\end{array}\right\\\\\left[\begin{array}{cc}x = 0\\x = 2\end{array}\right

#5.

8x^2 + 3x = 0\\x(8x + 3) = 0\\\\\left[\begin{array}{cc}x = 0\\8x +3 = 0\end{array}\right\\\\\left[\begin{array}{cc}x = 0\\8x = -3\end{array}\right\\\\\left[\begin{array}{cc}x = 0\\x = \frac{-3}{8} \end{array}\right

#6.

-x^2 + 8x = 0\\-x(x - 8) = 0\\\left[\begin{array}{cc}-x = 0\\x -8 = 0\end{array}\right\\\\\left[\begin{array}{cc}x = 0\\x = 8\end{array}\right

#7.

a)

x^2 + 1 = 82\\x^2 = 82 - 1\\x^2 = 81\\\\\left[\begin{array}{cc}x = 9\\x = -9\end{array}\right

б)

5x^2 = 20\\x^2 = 20 : 5\\x^2 = 4\\\\\left[\begin{array}{cc}x = 2\\x = -2\end{array}\right

в)

x^2 - 0,5x = 0\\x (x - 0,5) = 0\\\\\left[\begin{array}{cc}x = 0\\x -0,5 = 0\end{array}\right\\\\\left[\begin{array}{cc}x = 0\\x = 0,5\end{array}\right

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