第141页

信息发布者:
D
D
A
D
$18a$
$x + y$
$-9$
$5$
$m<\frac{5}{3}$且$m\neq\frac{1}{3}$
解:
$\begin{aligned}&\frac{a^{2}}{a^{2}-2a + 1}\cdot\frac{a - 1}{a}-\frac{1}{a - 1}\\=&\frac{a^{2}}{(a - 1)^{2}}\cdot\frac{a - 1}{a}-\frac{1}{a - 1}\\=&\frac{a}{a - 1}-\frac{1}{a - 1}\\=&\frac{a - 1}{a - 1}\\=&1\end{aligned}$
解:
$\begin{aligned}&(1-\frac{4}{a + 3})\div\frac{a^{2}-2a + 1}{2a + 6}\\=&(\frac{a + 3}{a + 3}-\frac{4}{a + 3})\div\frac{(a - 1)^{2}}{2(a + 3)}\\=&\frac{a + 3-4}{a + 3}\div\frac{(a - 1)^{2}}{2(a + 3)}\\=&\frac{a - 1}{a + 3}\cdot\frac{2(a + 3)}{(a - 1)^{2}}\\=&\frac{2}{a - 1}\end{aligned}$