1. 解下列方程:
(1)$2(x+3)=5x$;系数化为1,得$x=6$.
(2)$4x+3(2x-3)=12-(x+4)$;
(3)$6(\dfrac{1}{2}x - 4) + 2x = 7 - (\dfrac{1}{3}x - 1)$;
(4)$2 - 3(x+1) = 1 - 2(1 + 0.5x)$.
(3)去括号,得$3x - 24 + 2x = 7 - \dfrac{1}{3}x + 1$.
移项及合并同类项,得$\dfrac{16}{3}x = 32$.
(4)去括号,得$2 - 3x - 3 = 1 - 2 - x$.
移项及合并同类项,得$-2x = 0$.
系数化为1,得$x = 0$.
解:设它的宽是$x\ \mathrm{cm}$.
根据题意,得$6x = (6 - 2)(x + 2)$.
去括号,得$6x = 4x + 8$.
移项及合并同类项,得$2x = 8$.
系数化为1,得$x = 4$.
答:它的宽是$4\ \mathrm{cm}$.
(1)$2(x+3)=5x$;系数化为1,得$x=6$.
(2)$4x+3(2x-3)=12-(x+4)$;
(3)$6(\dfrac{1}{2}x - 4) + 2x = 7 - (\dfrac{1}{3}x - 1)$;
(4)$2 - 3(x+1) = 1 - 2(1 + 0.5x)$.
(3)去括号,得$3x - 24 + 2x = 7 - \dfrac{1}{3}x + 1$.
移项及合并同类项,得$\dfrac{16}{3}x = 32$.
(4)去括号,得$2 - 3x - 3 = 1 - 2 - x$.
移项及合并同类项,得$-2x = 0$.
系数化为1,得$x = 0$.
解:设它的宽是$x\ \mathrm{cm}$.
根据题意,得$6x = (6 - 2)(x + 2)$.
去括号,得$6x = 4x + 8$.
移项及合并同类项,得$2x = 8$.
系数化为1,得$x = 4$.
答:它的宽是$4\ \mathrm{cm}$.
答案:
问题4 如图5.2-1,翠湖在青山、绿水两地之间,距青山50 km,距绿水70 km. 某天,一辆汽车匀速行驶,途经王家庄、青山、绿水三地的时间如表5.2-1所示. 王家庄距翠湖的路程有多远?

答案: