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第67页

信息发布者：

2100

7.52

1.3

266

380

$\frac {7}{12}$

$\frac {5}{3}$

$\frac {40}{3}$

100

=450-103

=347

=5.8+4.4

=10.2

=25×8×0.4×125

=(25×0.4)×(8×125)

=10×1000

=10000

$ =(\frac {25}{49}+\frac {23}{49})×\frac {1}{12}$

$=\frac {48}{49}×\frac {1}{12}$

$=\frac {4}{49}$

$ =\frac {1}{4}×4×7+\frac {3}{7}×7×4$

$=1×7+3×4$

$=7+12$

$=19$

$=\frac {3}{4}÷[\frac {21}{20}×\frac {3}{7}]$

$=\frac {3}{4}÷\frac {9}{20}$

$=\frac {5}{3}$

$\begin {aligned}解： \frac {5}{12}x&=\frac {5}{8}\\x &=\frac {3}{2}\end {aligned}$

$\begin {aligned}解： 4x&=\frac {5}{7}×\frac {7}{15}\\4x&=\frac {1}{3}\\x &=\frac {1}{12}\end {aligned}$

$\begin {aligned}解： 0.5x&=5.2-3.5\\0.5x&=1.7\\x &=3.4\end {aligned}$