вправа 375 гдз 7 клас алгебра Мерзляк Полонський
7 клас ➠ алгебра ➠ Мерзляк Полонський
Вправа 375
Відповідь:
\begin{equation}1)\frac{x-7}{4}-\frac{x}{6}=2;\end{equation}
3x - 21 - 2x = 24;
x = 45; \begin{equation}2)\frac{x+6}{2}-\frac{x-7}{7}=4;\end{equation} 7(x + 6) - 2(x - 7) = 14 · 4;
7x + 42 - 2x + 14 = 56;
5x = 0; x = 0; \begin{equation}3)\frac{2x+3}{6}+\frac{1-4x}{8}=\frac{1}{3};\end{equation} \begin{equation}\frac{4\left ( 2x+3 \right )}{24}+\frac{3\left ( 1-4x \right )}{24}=\frac{8}{24};\end{equation} 8x + 12 + 3 - 12x = 8;
-4x = -7; \begin{equation}x=\frac{7}{4}=1,75;\end{equation} \begin{equation}4)3x-\frac{2x+3}{2}=\frac{x+6}{3};\end{equation} \begin{equation}\frac{6\cdot 3x}{6}-\frac{3\cdot \left ( 2x+3 \right )}{6}=\end{equation} \begin{equation}=\frac{2\cdot \left ( x+6 \right )}{6};\end{equation} 18x - 6x - 9 = 2x + 12;
10x = 21;
x = 2,1; \begin{equation}5)\frac{6x-7}{5}-\frac{3x+1}{6}=\frac{11-x}{15};\end{equation} \begin{equation}\frac{6\cdot \left ( 6x-7 \right )}{30}-\frac{5\cdot\left ( 3x+1 \right ) }{30}=\end{equation} \begin{equation}=\frac{2\cdot \left ( 11-x \right )}{30};\end{equation} 36x - 42 - 15x - 5 = 22 - 2x;
23x = 69;
x = 3; \begin{equation}6)\frac{5x-3}{9}-\frac{4x+3}{6}=x-1;\end{equation} \begin{equation}\frac{2\cdot \left ( 5x-3 \right )}{18}-\frac{3\cdot \left ( 4x+3 \right )}{18}=\end{equation} \begin{equation}=\frac{18\cdot \left ( x-1 \right )}{18};\end{equation} 10x - 6 - 12x - 9 = 18x - 18;
-20x = -3;
x = 0,15; \begin{equation}7)\frac{8x-5}{3}-\frac{4x+3}{4}+\frac{2-9x}{2}=-3;\end{equation} \begin{equation}\frac{4\cdot \left ( 8x-5 \right )}{12}-\frac{3\cdot \left ( 4x+3 \right )}{12}+\end{equation} \begin{equation}+\frac{6\cdot \left ( 2-9x \right )}{12}=\frac{-3\cdot 12}{12};\end{equation} 32x - 20 - 12x - 9 + 12 - 54x = -36;
-34x = -19; \begin{equation}x=\frac{19}{34};\end{equation} \begin{equation}8)\frac{8x^{2}-3x}{16}-\frac{6x^{2}+1}{12}=-1;\end{equation} \begin{equation}\frac{3\cdot \left ( 8x^{2}-3x \right )}{48}-\frac{4\cdot \left ( 6x^{2}+1 \right )}{48}=\end{equation} \begin{equation}=\frac{-1\cdot 48}{48};\end{equation} 24x² - 9x - 24x² - 4 = -48;
-9x = -44; \begin{equation}x=\frac{44}{9}=4\frac{8}{9}.\end{equation}
x = 45; \begin{equation}2)\frac{x+6}{2}-\frac{x-7}{7}=4;\end{equation} 7(x + 6) - 2(x - 7) = 14 · 4;
7x + 42 - 2x + 14 = 56;
5x = 0; x = 0; \begin{equation}3)\frac{2x+3}{6}+\frac{1-4x}{8}=\frac{1}{3};\end{equation} \begin{equation}\frac{4\left ( 2x+3 \right )}{24}+\frac{3\left ( 1-4x \right )}{24}=\frac{8}{24};\end{equation} 8x + 12 + 3 - 12x = 8;
-4x = -7; \begin{equation}x=\frac{7}{4}=1,75;\end{equation} \begin{equation}4)3x-\frac{2x+3}{2}=\frac{x+6}{3};\end{equation} \begin{equation}\frac{6\cdot 3x}{6}-\frac{3\cdot \left ( 2x+3 \right )}{6}=\end{equation} \begin{equation}=\frac{2\cdot \left ( x+6 \right )}{6};\end{equation} 18x - 6x - 9 = 2x + 12;
10x = 21;
x = 2,1; \begin{equation}5)\frac{6x-7}{5}-\frac{3x+1}{6}=\frac{11-x}{15};\end{equation} \begin{equation}\frac{6\cdot \left ( 6x-7 \right )}{30}-\frac{5\cdot\left ( 3x+1 \right ) }{30}=\end{equation} \begin{equation}=\frac{2\cdot \left ( 11-x \right )}{30};\end{equation} 36x - 42 - 15x - 5 = 22 - 2x;
23x = 69;
x = 3; \begin{equation}6)\frac{5x-3}{9}-\frac{4x+3}{6}=x-1;\end{equation} \begin{equation}\frac{2\cdot \left ( 5x-3 \right )}{18}-\frac{3\cdot \left ( 4x+3 \right )}{18}=\end{equation} \begin{equation}=\frac{18\cdot \left ( x-1 \right )}{18};\end{equation} 10x - 6 - 12x - 9 = 18x - 18;
-20x = -3;
x = 0,15; \begin{equation}7)\frac{8x-5}{3}-\frac{4x+3}{4}+\frac{2-9x}{2}=-3;\end{equation} \begin{equation}\frac{4\cdot \left ( 8x-5 \right )}{12}-\frac{3\cdot \left ( 4x+3 \right )}{12}+\end{equation} \begin{equation}+\frac{6\cdot \left ( 2-9x \right )}{12}=\frac{-3\cdot 12}{12};\end{equation} 32x - 20 - 12x - 9 + 12 - 54x = -36;
-34x = -19; \begin{equation}x=\frac{19}{34};\end{equation} \begin{equation}8)\frac{8x^{2}-3x}{16}-\frac{6x^{2}+1}{12}=-1;\end{equation} \begin{equation}\frac{3\cdot \left ( 8x^{2}-3x \right )}{48}-\frac{4\cdot \left ( 6x^{2}+1 \right )}{48}=\end{equation} \begin{equation}=\frac{-1\cdot 48}{48};\end{equation} 24x² - 9x - 24x² - 4 = -48;
-9x = -44; \begin{equation}x=\frac{44}{9}=4\frac{8}{9}.\end{equation}