12. 解下列不等式(组),并在数轴上表示解集:
(1)$\frac {x-2}{3}-\frac {5-2x}{5}<x-3$;
(2)$\left\{\begin{array}{l} x-2<0,\\ 2(2x-1)≤1+5x.\end{array} \right. $
(1)$\frac {x-2}{3}-\frac {5-2x}{5}<x-3$;
(2)$\left\{\begin{array}{l} x-2<0,\\ 2(2x-1)≤1+5x.\end{array} \right. $
答案
12. (1)$x > 5$,数轴略;(2)$-3 \leq x < 2$,数轴略.
13. $x$取哪些整数值时,不等式$5x-1>3(x+1)与\frac {1}{2}x-1≤7-\frac {3}{2}x$都成立?
答案
13. $x$可以取3或4.
14. 解一元一次不等式组:$\left\{\begin{array}{l} 2x+5≤3(x+2),\\ 2x-\frac {1+3x}{2}<1,\end{array} \right. $在数轴上表示解集,并写出它的非负整数解.
答案
14. $-1 \leq x < 3$,数轴略,非负整数解为0;1;2.
登录