Алгебра 8 класс учебник Макарычев, Миндюк ответы – номер 989

а) $$ \left\{\begin{array} { l } { \frac { x } { 3 } + \frac { x } { 4 } < 7 } \\ { 1 - \frac { x } { 6 } > 0 } \end{array} \left\{\begin{array} { l } { \frac { 4 x } { 1 2 } + \frac { 3 x } { 1 2 } < 7 } \\ { \frac { 6 } { 6 } - \frac { x } { 6 } > 0 } \end{array} \left\{\begin{array}{l} \frac{7 x}{12}<7 \\ \frac{6-x}{6}>0 \end{array}\right.\right.\right. $$ $$ \left\{\begin{array} { l } { 7 x < 7 \unrhd 2 } \\ { 6 - x > 0 } \end{array} \left\{\begin{array} { l } { x < \frac { 7 · 1 2 } { 7 } } \\ { - x > - 6 } \end{array} \left\{\begin{array}{l} x<12 \\ x<6 \end{array}\right.\right.\right. $$

    (−∞; 6)
б) $$ \left\{\begin{array} { l } { y - \frac { y - 1 } { 2 } > 1 } \\ { \frac { y } { 3 } < 5 } \end{array} \left\{\begin{array}{l} \frac{2 y-y+1}{2}>1 \\ y<5 · 3]{ } \end{array}\right.\right. $$ $$ \left\{\begin{array} { l } { y + 1 > 1 } \\ { y < 1 5 } \end{array} \left\{\begin{array} { l } { y > 2 - 1 } \\ { y < 1 5 } \end{array} \left\{\begin{array}{l} y>1 \\ y<15 \end{array}\right.\right.\right. $$

    (1; 15)
в) $$ \left\{\begin{array} { l } { \frac { 3 x - 1 } { 2 } - x \leq 2 } \\ { 2 x - \frac { x } { 3 } \geq 1 } \end{array} \left\{\begin{array} { l } { \frac { 3 x - 1 - 2 x } { 2 } \leq 2 } \\ { \frac { 6 x - x } { 3 } \geq 1 } \end{array} \left\{\begin{array}{l} \frac{x-1}{2} \leq 2 \\ \frac{5 x}{3} \geq 1 \end{array}\right.\right.\right. $$ $$ \left\{\begin{array} { l } { x - 1 \leq 2 · { 2 } } \\ { 5 x \geq 1 · { 3 } } \end{array} \left\{\begin{array} { l } { x \leq 4 + 1 } \\ { x \geq 3 : 5 } \end{array} \left\{\begin{array}{l} x \leq 5 \\ x \geq 0,6 \end{array}\right.\right.\right. $$

    [0,6; 5]
г) $$ \left\{\begin{array}{l} 2 p-\frac{p-2}{5}>4\left\{\begin{array} { l } { \frac { 1 0 p - p + 2 } { 5 } > 4 } \\ { \frac { p } { 2 } - \frac { p } { 8 } \leq 6 } \end{array} \left\{\begin{array}{l} \frac{9 p+2}{5}>4 \\ \frac{4 p-p}{8} \leq 6 \end{array}\left\{\begin{array}{l} \frac{3 p}{8} \leq 6 \end{array}\right\}\right.\right. \end{array}\right. $$ $$ \left\{\begin{array} { l } { 9 p + 2 > 4 5 5 } \\ { 3 p \leq 6 8 } \end{array} \left\{\begin{array} { l } { 9 p > 2 0 - 2 } \\ { 3 p \leq 4 8 } \end{array} \left\{\begin{array} { l } { p > 1 8 : 9 } \\ { p \leq 4 8 : 3 } \end{array} \left\{\begin{array}{l} p>2 \\ p \leq 16 \end{array}\right.\right.\right.\right. $$

    (2; 16]