第54页

信息发布者:
$8.5a+6.5b$
$\frac{180-a}{2}$
$\frac{b}{5}$
$140\%x$
$3a$
$3a+6$
$4n-2$
解:$\begin{aligned}0.4x&=4-1.6\\0.4x&=2.4\\x&=6\end{aligned}$
解:$\begin{aligned}(0.4-0.18)x&=44\\0.22x&=44\\x&=200\end{aligned}$
解:$\begin{aligned}(1+\frac{2}{5})x&=\frac{9}{14}\\frac{7}{5}x&=\frac{9}{14}\\x&=\frac{45}{98}\end{aligned}$
解:$\begin{aligned}7x&=2×4.5\\x&=\frac{9}{7}\end{aligned}$
A
C
C
B
46.4
50
5
30
25

196