Question

11．解方程．
x-25%x=0.75
$\frac{1}{4}x÷\frac{4}{9}=\frac{2}{3}$．

Answer 1

分析 ①算出左邊是0.75x，然后利用等式的性質(zhì)，方程兩邊同時(shí)除以0.75；
②方程兩邊同時(shí)乘$\frac{4}{9}$，然后兩邊再同時(shí)除以$\frac{1}{4}$．

解答 解：①x-25%x=0.75
             0.75x=0.75
     0.75x÷0.75=0.75÷0.75
                   x=1

②$\frac{1}{4}x÷\frac{4}{9}=\frac{2}{3}$
$\frac{1}{4}$x$÷\frac{4}{9}$×$\frac{4}{9}$=$\frac{2}{3}$×$\frac{4}{9}$
         $\frac{1}{4}$x=$\frac{8}{27}$
    $\frac{1}{4}$x$÷\frac{1}{4}$=$\frac{8}{27}$$÷\frac{1}{4}$
            x=$\frac{32}{27}$

點(diǎn)評(píng) 應(yīng)用等式的性質(zhì)解方程，要注意等于號(hào)要對(duì)齊．