解答 - 绝对值方程

$$\left(\frac{2}{5}y\right)-\frac{4}{5}·y=\left(\frac{4}{5}y\right)-\frac{4}{5}y$$

组合分数:

$$\frac{\left(2-4\right)}{5}·y=\left(\frac{4}{5}·y\right)-\frac{4}{5}y$$

合并分子:

$$\frac{-2}{5}·y=\left(\frac{4}{5}·y\right)-\frac{4}{5}y$$

组合分数:

$$\frac{-2}{5}·y=\frac{\left(4-4\right)}{5}y$$

合并分子:

$$\frac{-2}{5}·y=\frac{0}{5}y$$

分子为零则整体为零:

$$\frac{-2}{5}y=0y$$

简化运算:

$$\frac{-2}{5}y=0$$

两边都除以系数:

$$y=0$$

$$\left(\frac{2}{5}y\right)·\frac{5}{2}=\left(\frac{-4}{5}y\right)·\frac{5}{2}$$

收集同类项:

$$\left(\frac{2}{5}·\frac{5}{2}\right)y=\left(\frac{-4}{5}y\right)·\frac{5}{2}$$

系数之间相乘:

$$\frac{\left(2·5\right)}{\left(5·2\right)}·y=\left(\frac{-4}{5}y\right)·\frac{5}{2}$$

简化分数:

$$y=\left(\frac{-4}{5}y\right)·\frac{5}{2}$$

收集同类项:

$$y=\left(\frac{-4}{5}·\frac{5}{2}\right)y$$

系数之间相乘:

$$y=\frac{\left(-4·5\right)}{\left(5·2\right)}y$$

简化运算:

$$y=-2y$$

将 $$$$ 加到等式的两边:

$$y+2y=\left(-2y\right)+2y$$

简化运算:

$$3y=\left(-2y\right)+2y$$

简化运算:

$$3y=0$$

两边都除以系数:

$$y=0$$