Решебник по алгебре 7 класс Мерзляк ФГОС Задание 1163

 

\[\boxed{\text{1163\ (1163).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[1)\ 2,49 \cdot 1,35 - 1,35 \cdot 1,84 + {1,35}^{2} =\]

\[= 1,35 \cdot (2,49 - 1,84 + 1,35) =\]

\[= 1,35 \cdot 2 = 2,7.\]

\[= 0,25 \cdot 1,6 \cdot (0,25 + 1,6 - 0,85) =\]

\[= 0,4 \cdot 1 = 0,4.\]

\[= 3,24 \cdot 2,3 + 2,3 \cdot 6,76 =\]

\[= 2,3 \cdot (3,24 + 6,76) =\]

\[= 2,3 \cdot 10 = 23.\]

\[4)\ 5,12 \cdot 9,76 + 5,12 \cdot 5,36 - {5,12}^{2} =\]

\[= 5,12 \cdot (9,76 + 5,36 - 5,12) =\]

\[= 5,12 \cdot 10 = 51,2.\ \]

\[\boxed{\text{1163.\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[1)\ x + y = 12\]

\[x = 12 - y\ \]

\[(1;11),\ (0;12),\ (15;\ - 3).\]

\[2)\ x - 7y = 5\ \ \]

\[x = 5 + 7y\ \]

\[(12;1),\ (5;0),\ (19;2).\]

\[3)\ x + 6y = 10\]

\[x = 10 - 6y\]

\[(10;0);(4;1);( - 2;2).\]

\[4)\ 2x + 8y = 16\ \ \ |\ \ :2\]

\[x + 4y = 8\ \ \]

\[x = 8 - 4y\]

\[(8;0),\ (4;1),\ (12;\ - 1)\]

\[5) - 6x + 5y = 18,\ \ \]

\[- 6x = 18 - 5y\ \]

\[6x = 5y - 18\]

\[x = \frac{5}{6}y - 3\]

\[( - 3;0),\ (7;12),\ (2;6).\]

\[6)\ 3x - 7y = 1\]

\[3x = 1 + 7y\]

\[x = \frac{1}{3} + \frac{7}{3}y = \frac{1}{3} + 2\frac{1}{3}y\]

\[\left( \frac{1}{3};0 \right);\left( 7\frac{1}{3};3 \right);\left( 0;\ - \frac{1}{7} \right).\]